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2016 Volume 27 Issue 8
2016, 27(8): 1097-1104
doi: 10.1016/j.cclet.2016.05.005
Abstract:
Design and synthesis of new organic functional materials with improved performance or novel properties are of great importance in the field of optoelectronics. Azulene, as a non-alternant aromatic hydrocarbon, has attracted rising attention in the last few years. Different from most common aromatic hydrocarbons, azulene has unique characteristics, including large dipole moment, small gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). However, the design and synthesis of azulene-based functional materials are still facing several challenges. This review focuses on the recent development of organic functional materials employing azulene unit. The synthesis of various functionalized azulene derivatives is summarized and their applications in optoelectronics are discussed, with particular attention to the fields including nonlinear optics (NLO), organic field-effect transistors (OFETs), solar cells, and molecular devices.
Design and synthesis of new organic functional materials with improved performance or novel properties are of great importance in the field of optoelectronics. Azulene, as a non-alternant aromatic hydrocarbon, has attracted rising attention in the last few years. Different from most common aromatic hydrocarbons, azulene has unique characteristics, including large dipole moment, small gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). However, the design and synthesis of azulene-based functional materials are still facing several challenges. This review focuses on the recent development of organic functional materials employing azulene unit. The synthesis of various functionalized azulene derivatives is summarized and their applications in optoelectronics are discussed, with particular attention to the fields including nonlinear optics (NLO), organic field-effect transistors (OFETs), solar cells, and molecular devices.
2016, 27(8): 1105-1114
doi: 10.1016/j.cclet.2016.05.018
Abstract:
This paper summarizes our recent progress on the preparations and applications of electropolymerized thin films of redox-active ruthenium complexes. Thin films of vinyl-functionalized diruthenium or ruthenium-amine conjugated complexes are prepared by reductive electropolymerization. The resulting films are useful for multistate near-infrared electrochromism, ion sensing, and mimicking flip-flop and flip-flap-flop logic gates. The oxidative electropolymerization of diruthenium complexes with two distal triarylamine units affords electropolymers with an alternating diruthenium and tetraphenylbenzidine structural unit. The applications of the resulting films in multistate near-infrared electrochromism and resistive memory are discussed.
This paper summarizes our recent progress on the preparations and applications of electropolymerized thin films of redox-active ruthenium complexes. Thin films of vinyl-functionalized diruthenium or ruthenium-amine conjugated complexes are prepared by reductive electropolymerization. The resulting films are useful for multistate near-infrared electrochromism, ion sensing, and mimicking flip-flop and flip-flap-flop logic gates. The oxidative electropolymerization of diruthenium complexes with two distal triarylamine units affords electropolymers with an alternating diruthenium and tetraphenylbenzidine structural unit. The applications of the resulting films in multistate near-infrared electrochromism and resistive memory are discussed.
2016, 27(8): 1115-1123
doi: 10.1016/j.cclet.2016.06.031
Abstract:
Through-space conjugated molecules are interesting building blocks for the construction of functional materials that allow multi-dimensional transport of carrier and energy. However, the well explored through-space conjugated molecules are quite limited, which defers their structure-property correlation establishment and wide-scale application. In this review, we introduce a kind of newly-emerging folded tetraphenylethene derivatives featuring through-space conjugation. Their synthesis, crystal and electronic structures, and optical properties are described, and their representative applications as bipolar charge-transporting materials in organic light-emitting diodes and as single-molecule wires in molecular devices are presented, which are anticipated to provide guidance for the further expansion of through-space conjugated systems.
Through-space conjugated molecules are interesting building blocks for the construction of functional materials that allow multi-dimensional transport of carrier and energy. However, the well explored through-space conjugated molecules are quite limited, which defers their structure-property correlation establishment and wide-scale application. In this review, we introduce a kind of newly-emerging folded tetraphenylethene derivatives featuring through-space conjugation. Their synthesis, crystal and electronic structures, and optical properties are described, and their representative applications as bipolar charge-transporting materials in organic light-emitting diodes and as single-molecule wires in molecular devices are presented, which are anticipated to provide guidance for the further expansion of through-space conjugated systems.
2016, 27(8): 1124-1130
doi: 10.1016/j.cclet.2016.06.047
Abstract:
In recent two years, organometal halide perovskites quantum dots are emerging as a new member of the nanocrystals family. From the chemical point of view, these perovskites quantum dots can be synthesized either by classical hot-injection technique for inorganic semiconductor quantum dots or the reprecipitation synthesis at room temperature for organic nanocrystals. From a physical point of view, the observed large exciton binding energy, well self-passivated surface, as well as the enhanced nonlinear properties have been of great interest for fundamental study. From the application point of view, these perovskites quantum dots exhibit high photoluminescence quantum yields, wide wavelength tunability and ultra-narrow band emissions, the combination of these superior optical properties and low cost fabrication makes them to be suitable candidates for display technology. In this short review, we introduce the synthesis, optical properties, the prototype light-emitting devices, and the current important research tasks of halide perovsktie quantum dots, with an emphasis on CH3NH3PbX3 (X=Cl, Br, I) quantum dots that developed in our group.
In recent two years, organometal halide perovskites quantum dots are emerging as a new member of the nanocrystals family. From the chemical point of view, these perovskites quantum dots can be synthesized either by classical hot-injection technique for inorganic semiconductor quantum dots or the reprecipitation synthesis at room temperature for organic nanocrystals. From a physical point of view, the observed large exciton binding energy, well self-passivated surface, as well as the enhanced nonlinear properties have been of great interest for fundamental study. From the application point of view, these perovskites quantum dots exhibit high photoluminescence quantum yields, wide wavelength tunability and ultra-narrow band emissions, the combination of these superior optical properties and low cost fabrication makes them to be suitable candidates for display technology. In this short review, we introduce the synthesis, optical properties, the prototype light-emitting devices, and the current important research tasks of halide perovsktie quantum dots, with an emphasis on CH3NH3PbX3 (X=Cl, Br, I) quantum dots that developed in our group.
2016, 27(8): 1131-1138
doi: 10.1016/j.cclet.2016.06.007
Abstract:
The incorporation of B element into p-conjugated system is an efficient strategy to tune the steric and electronic structure and thus optoelectronic properties of π-electron systems. The vacant p orbital on the tricoordinate B center makes it exhibit several electronic and steric features, such as electron-accepting ability through p-π* conjugation, the high Lewis acidity to coordinate with Lewis bases, as well as the steric bulk arising from the aryl substituent on the B center to get enough kinetic stability. As a result, the boryl group is a very unique electron acceptor. When an electron-donating amino group is present, the triarylboranes would display intense intramolecular charge transfer transitions, which lead to interesting optoelectronic properties and great utilities. This short review summarizes the recent progress in π-electron systems, which contain both B and N elements and thus display intramolecular charge-transfer transitions. The triarylboranes are introduced based on their structural features, including the linear π-system with boryl and amino groups at the terminal positions, the lateral borylsubstituted π-system with amino groups at the terminal positions, the biphenyl π-system with an amino and a boryl groups at o,o'-positions, nonconjugated U- and V-shaped π-system, macrocylcic π-system with B and N embedded in the ring, B,N-bridged ladder-type π-system, as well as the polycyclic π-system with B embedded in the center.
The incorporation of B element into p-conjugated system is an efficient strategy to tune the steric and electronic structure and thus optoelectronic properties of π-electron systems. The vacant p orbital on the tricoordinate B center makes it exhibit several electronic and steric features, such as electron-accepting ability through p-π* conjugation, the high Lewis acidity to coordinate with Lewis bases, as well as the steric bulk arising from the aryl substituent on the B center to get enough kinetic stability. As a result, the boryl group is a very unique electron acceptor. When an electron-donating amino group is present, the triarylboranes would display intense intramolecular charge transfer transitions, which lead to interesting optoelectronic properties and great utilities. This short review summarizes the recent progress in π-electron systems, which contain both B and N elements and thus display intramolecular charge-transfer transitions. The triarylboranes are introduced based on their structural features, including the linear π-system with boryl and amino groups at the terminal positions, the lateral borylsubstituted π-system with amino groups at the terminal positions, the biphenyl π-system with an amino and a boryl groups at o,o'-positions, nonconjugated U- and V-shaped π-system, macrocylcic π-system with B and N embedded in the ring, B,N-bridged ladder-type π-system, as well as the polycyclic π-system with B embedded in the center.
2016, 27(8): 1139-1146
doi: 10.1016/j.cclet.2016.06.014
Abstract:
The knowledge of azaborine chemistry is growing as an important branch in organic semiconductor materials. Specifically, BN-embedded aromatic compounds have attracted great attention due to their fascinating properties resulted from the replacement of CC unit with isoelectronic BN unit in aromatics. Though great insights have been provided into the synthetic chemistry and photophysical properties of BN-embedded aromatics, their applications in optoelectronic areas are still at a young stage. This short review summarizes the recent progress of BN-embedded aromatics with optoelectronic applications in organic field-effect transistors, organic light-emitting diodes, organic photovoltaics, stimuli-responsive luminescent devices, and chemical sensors.
The knowledge of azaborine chemistry is growing as an important branch in organic semiconductor materials. Specifically, BN-embedded aromatic compounds have attracted great attention due to their fascinating properties resulted from the replacement of CC unit with isoelectronic BN unit in aromatics. Though great insights have been provided into the synthetic chemistry and photophysical properties of BN-embedded aromatics, their applications in optoelectronic areas are still at a young stage. This short review summarizes the recent progress of BN-embedded aromatics with optoelectronic applications in organic field-effect transistors, organic light-emitting diodes, organic photovoltaics, stimuli-responsive luminescent devices, and chemical sensors.
2016, 27(8): 1147-1154
doi: 10.1016/j.cclet.2016.06.054
Abstract:
Organoplatinum(II) compounds have received enormous attention over the past decades due to their square-planar geometry as well as intriguing photo-physical properties. Self-assembly has emerged as an excellent approach to create well-ordered supramolecular architectures with tunable properties, which underpin the role of solvent-directed approach for the design of functional materials. In this minireview, the recent advances on supramolecular self-assembly of cyclometalated platinum(II) complexes have been discussed. During the self-assembly process, non-covalent Pt-Pt and π-π interactions play crucial roles in controlling the structures and functions of the resulting assemblies.
Organoplatinum(II) compounds have received enormous attention over the past decades due to their square-planar geometry as well as intriguing photo-physical properties. Self-assembly has emerged as an excellent approach to create well-ordered supramolecular architectures with tunable properties, which underpin the role of solvent-directed approach for the design of functional materials. In this minireview, the recent advances on supramolecular self-assembly of cyclometalated platinum(II) complexes have been discussed. During the self-assembly process, non-covalent Pt-Pt and π-π interactions play crucial roles in controlling the structures and functions of the resulting assemblies.
2016, 27(8): 1155-1165
doi: 10.1016/j.cclet.2016.04.003
Abstract:
π-Conjugated organic luminescent materials are essential components for modern optical and photoelectric research. This review mainly probes into the recent work in the progress of smart π-conjugated organic systems in the form of cyanostilbene and its derivatives, which can regulate its excellent features in response to a variety of physical or chemical stimuli (e.g. viscosity, light, magnetism, electric field, polarity, pH and solvent environment). As a result of its extensive applicability and adaptability, cyanostilbene and its derivatives have been planted into different structural architectures such as polymers, functional nanoparticles, solid membranes, supramolecular systems and so on. This review will first give a general description of the preparation and characterization of cyanostilbenebased optoelectric luminophores and then focus on their peculiar functional properties in the need for advanced material applications, such as AIEE (aggregation-induced enhanced emission effect), solidstate emission, photovoltaics, photolithography and photochromism to be further processed afterwards. The purpose of this review is to give a platform of practical organic materials, mostly cyanostilbene and its derivatives, based on stable aromatic derivatives, to contribute to the booming of modern π-conjugated photoelectric materials that integrate with contemporary physics, material chemistry, bioengineering, medical science and aerospace altogether.
π-Conjugated organic luminescent materials are essential components for modern optical and photoelectric research. This review mainly probes into the recent work in the progress of smart π-conjugated organic systems in the form of cyanostilbene and its derivatives, which can regulate its excellent features in response to a variety of physical or chemical stimuli (e.g. viscosity, light, magnetism, electric field, polarity, pH and solvent environment). As a result of its extensive applicability and adaptability, cyanostilbene and its derivatives have been planted into different structural architectures such as polymers, functional nanoparticles, solid membranes, supramolecular systems and so on. This review will first give a general description of the preparation and characterization of cyanostilbenebased optoelectric luminophores and then focus on their peculiar functional properties in the need for advanced material applications, such as AIEE (aggregation-induced enhanced emission effect), solidstate emission, photovoltaics, photolithography and photochromism to be further processed afterwards. The purpose of this review is to give a platform of practical organic materials, mostly cyanostilbene and its derivatives, based on stable aromatic derivatives, to contribute to the booming of modern π-conjugated photoelectric materials that integrate with contemporary physics, material chemistry, bioengineering, medical science and aerospace altogether.
2016, 27(8): 1166-1174
doi: 10.1016/j.cclet.2016.06.028
Abstract:
The conjugated polycycles show excellent optical and electrical properties that are suitable for application in various organic electronics. While most of attentions have been paid to polycycles having planar π-conjugated system, the curved polycycles seem amazing due to their unique physical and chemical features. The non-planar conjugated polycycles have been created with the geometries of bracelet, saddle, bowl, Möbius band, helicenes, etc. Among them, the bowl-shaped one is of growing interest owing to the multidiscipline applications such as synthetic intermediates for end-cap of carbon nanotube, coordination with metal ions, encapsulation of fullerenes, and fabrication of electronic devices. In this paper, we summarize the recent advances on the chemistry of the bowl-shaped conjugated polycycles, particularly on their synthesis and the further chemical modifications toward organic functional materials.
The conjugated polycycles show excellent optical and electrical properties that are suitable for application in various organic electronics. While most of attentions have been paid to polycycles having planar π-conjugated system, the curved polycycles seem amazing due to their unique physical and chemical features. The non-planar conjugated polycycles have been created with the geometries of bracelet, saddle, bowl, Möbius band, helicenes, etc. Among them, the bowl-shaped one is of growing interest owing to the multidiscipline applications such as synthetic intermediates for end-cap of carbon nanotube, coordination with metal ions, encapsulation of fullerenes, and fabrication of electronic devices. In this paper, we summarize the recent advances on the chemistry of the bowl-shaped conjugated polycycles, particularly on their synthesis and the further chemical modifications toward organic functional materials.
2016, 27(8): 1175-1183
doi: 10.1016/j.cclet.2016.06.033
Abstract:
This paper intends to provide an overview for using corannulene derivatives in organic electronics such as organic field-effect transistors (OFETs), organic solar cells (OSCs), and organic light-emitting diodes (OLEDs). We highlight the rational design strategies, tuning molecular orbital energy levels and arrangement in single crystals of corannulenes. The topological structure and properties of corannulene make it a unique candidate for organic electronics.
This paper intends to provide an overview for using corannulene derivatives in organic electronics such as organic field-effect transistors (OFETs), organic solar cells (OSCs), and organic light-emitting diodes (OLEDs). We highlight the rational design strategies, tuning molecular orbital energy levels and arrangement in single crystals of corannulenes. The topological structure and properties of corannulene make it a unique candidate for organic electronics.
2016, 27(8): 1184-1192
doi: 10.1016/j.cclet.2016.05.026
Abstract:
This review summarizes the recent progress of efficient room temperature phosphorescence (RTP) from pure organic luminogens achieved by crystallization-induced phosphorescence (CIP), with focus on the advances in our group. Besides homocrystals, mixed crystals and cocrystals are also discussed. Meanwhile, intriguing RTP emission from the luminogens without conventional chromophores is demonstrated.
This review summarizes the recent progress of efficient room temperature phosphorescence (RTP) from pure organic luminogens achieved by crystallization-induced phosphorescence (CIP), with focus on the advances in our group. Besides homocrystals, mixed crystals and cocrystals are also discussed. Meanwhile, intriguing RTP emission from the luminogens without conventional chromophores is demonstrated.
2016, 27(8): 1193-1200
doi: 10.1016/j.cclet.2016.07.009
Abstract:
Iridium(III) complexes are one of the most important electrophosphorescent dyes with tunable emissions in the range of visible and near infrared lights, high photoluminescence yields and short lifetimes for high-efficiency organic light-emitting diodes (OLED) with 100% exciton harvesting. This review summarizes the recent development of electroluminescent Ir3+ complexes functionalized with host-featured carrier-transporting groups, with emphasis on correlations between functionalization, optoelectronic properties and device performance. According to the introducing approaches, the complexes were sorted with conjugated and aliphatic linkages, as well as the types of functional groups. The modification effect on physical properties and the state-of-the-art device performances were discussed.
Iridium(III) complexes are one of the most important electrophosphorescent dyes with tunable emissions in the range of visible and near infrared lights, high photoluminescence yields and short lifetimes for high-efficiency organic light-emitting diodes (OLED) with 100% exciton harvesting. This review summarizes the recent development of electroluminescent Ir3+ complexes functionalized with host-featured carrier-transporting groups, with emphasis on correlations between functionalization, optoelectronic properties and device performance. According to the introducing approaches, the complexes were sorted with conjugated and aliphatic linkages, as well as the types of functional groups. The modification effect on physical properties and the state-of-the-art device performances were discussed.
2016, 27(8): 1201-1208
doi: 10.1016/j.cclet.2016.07.006
Abstract:
Compared with conventional p-conjugated polymers, poly(arylene ether)s (PAEs) may take advantages of excellent thermal properties, well-defined effective conjugated length and no catalyst contamination. Recently, their applications have been extended from engineering plastics to optoelectronic materials. In this review, various kinds of functional PAEs used as fluorescent polymers, host polymers and phosphorescent polymers in organic light-emitting diodes (OLEDs) are outlined, and their molecular design, synthesis and device performance are overviewed.
Compared with conventional p-conjugated polymers, poly(arylene ether)s (PAEs) may take advantages of excellent thermal properties, well-defined effective conjugated length and no catalyst contamination. Recently, their applications have been extended from engineering plastics to optoelectronic materials. In this review, various kinds of functional PAEs used as fluorescent polymers, host polymers and phosphorescent polymers in organic light-emitting diodes (OLEDs) are outlined, and their molecular design, synthesis and device performance are overviewed.
2016, 27(8): 1209-1222
doi: 10.1016/j.cclet.2016.05.031
Abstract:
Exploring the charge transport properties and electronic functions of molecules is of primary interest in the area of molecular electronics. Conjugated polymers (CPs) represent an attractive class of molecular candidates, benefiting from their outstanding optoelectronic properties. However, they have been less studied compared with the small-molecule family, mainly due to the difficulties in incorporating CPs into molecular junctions. In this review, we present a summary on how to fabricate CP-based singlechain and monolayered junctions, then discuss the transport behaviors of CPs in different junction architectures and finally introduce the potential applications of CPs in molecular-scale electronic devices. Although the research on CP-based molecular electronics is still at the initial stage, it is widely accepted that (1) CP chains are able to mediate long-range charge transport if their molecular electronic structures are properly designed, which makes them potential molecular wires, and (2) the intrinsic optoelectronic properties of CPs and the possibility of incorporating desirable functionalities by synthetic strategies imply the potential of employing tailor-made polymeric components as alternatives to small molecules for future molecular-scale electronics.
Exploring the charge transport properties and electronic functions of molecules is of primary interest in the area of molecular electronics. Conjugated polymers (CPs) represent an attractive class of molecular candidates, benefiting from their outstanding optoelectronic properties. However, they have been less studied compared with the small-molecule family, mainly due to the difficulties in incorporating CPs into molecular junctions. In this review, we present a summary on how to fabricate CP-based singlechain and monolayered junctions, then discuss the transport behaviors of CPs in different junction architectures and finally introduce the potential applications of CPs in molecular-scale electronic devices. Although the research on CP-based molecular electronics is still at the initial stage, it is widely accepted that (1) CP chains are able to mediate long-range charge transport if their molecular electronic structures are properly designed, which makes them potential molecular wires, and (2) the intrinsic optoelectronic properties of CPs and the possibility of incorporating desirable functionalities by synthetic strategies imply the potential of employing tailor-made polymeric components as alternatives to small molecules for future molecular-scale electronics.
2016, 27(8): 1223-1230
doi: 10.1016/j.cclet.2016.06.002
Abstract:
The development of fluorescent materials capable of harvesting triplet excitons efficiently is of great importance in achieving high-performance low-cost organic light-emitting diodes (OLEDs). Among the three mechanisms converting triplet to singlet excitons, triplet fusion delayed fluorescence (TFDF) plays a key role in the demonstration of highly efficient and reliable OLEDs, especially blue devices, for practice applications. This review focuses on the recent development of TFDF materials and their applications in OLEDs. Fundamental TFDF mechanism, molecular design principles, and the structure-property relationship of TFDF materials with a particular emphasis on their different excited state characters, are presented and discussed. Moreover, the future perspectives and ongoing challenges of TFDF materials are also highlighted.
The development of fluorescent materials capable of harvesting triplet excitons efficiently is of great importance in achieving high-performance low-cost organic light-emitting diodes (OLEDs). Among the three mechanisms converting triplet to singlet excitons, triplet fusion delayed fluorescence (TFDF) plays a key role in the demonstration of highly efficient and reliable OLEDs, especially blue devices, for practice applications. This review focuses on the recent development of TFDF materials and their applications in OLEDs. Fundamental TFDF mechanism, molecular design principles, and the structure-property relationship of TFDF materials with a particular emphasis on their different excited state characters, are presented and discussed. Moreover, the future perspectives and ongoing challenges of TFDF materials are also highlighted.
2016, 27(8): 1231-1240
doi: 10.1016/j.cclet.2016.06.029
Abstract:
Room-temperature phosphorescence (RTP) materials have attracted great attention due to their involvement of excited triplet states and comparatively long decay lifetimes. In this short review, recent progress on enhancement of RTP from purely organic materials is summarized. According to the mechanism of phosphorescence emission, two principles are discussed to construct efficient RTP materials: one is promoting intersystem crossing (ISC) efficiency by using aromatic carbonyl, heavyatom, or/and heterocycle/heteroatom containing compounds; the other is suppressing intramolecular motion and intermolecular collision which can quench excited triplet states, including embedding phosphors into polymers and packing them tightly in crystals. With aforementioned strategies, RTP from purely organic materials was achieved both in fluid and rigid media.
Room-temperature phosphorescence (RTP) materials have attracted great attention due to their involvement of excited triplet states and comparatively long decay lifetimes. In this short review, recent progress on enhancement of RTP from purely organic materials is summarized. According to the mechanism of phosphorescence emission, two principles are discussed to construct efficient RTP materials: one is promoting intersystem crossing (ISC) efficiency by using aromatic carbonyl, heavyatom, or/and heterocycle/heteroatom containing compounds; the other is suppressing intramolecular motion and intermolecular collision which can quench excited triplet states, including embedding phosphors into polymers and packing them tightly in crystals. With aforementioned strategies, RTP from purely organic materials was achieved both in fluid and rigid media.
2016, 27(8): 1241-1249
doi: 10.1016/j.cclet.2016.05.006
Abstract:
This review paper summarizes the recent progress of highly efficient copolymers with the fluorination strategy for photovoltaic applications. We first present a brief introduction of the fundamental principles of polymer solar cells, and then the functions of fluorine atoms on the polymer donor materials. Finally, we review the research progress of the reported copolymers by classification of the fluorinated acceptor units and donor units, respectively. The resulting structure-property correlations of these copolymers are also discussed which shall certainly facilitate widespread utilization of this strategy for constructing high-performance photovoltaic copolymers in the future.
This review paper summarizes the recent progress of highly efficient copolymers with the fluorination strategy for photovoltaic applications. We first present a brief introduction of the fundamental principles of polymer solar cells, and then the functions of fluorine atoms on the polymer donor materials. Finally, we review the research progress of the reported copolymers by classification of the fluorinated acceptor units and donor units, respectively. The resulting structure-property correlations of these copolymers are also discussed which shall certainly facilitate widespread utilization of this strategy for constructing high-performance photovoltaic copolymers in the future.
2016, 27(8): 1250-1258
doi: 10.1016/j.cclet.2016.07.018
Abstract:
The application of heavy-metal complexes in bulk-heterojunction (BHJ) solar cells is a promising new research field which has attracted increasing attention, due to their strong spin-orbit coupling for efficient singlet to triplet intersystem crossing. This review article focuses on recent advances of heavy metal complex containing organic and polymer materials as photovoltaic donors in BHJ solar cells. Platinum-acetylide containing oligomersor and polymers have been firstly illustrated due to the good solubility, square planar structure, as well as the fairly strong Pt-Pt interaction. Then the cyclometalated Pt or Ir complex containing conjugated oligomers and polymers are presented in which the triplet organometallic compounds are embedded into the organic/polymer backbone either through cyclometalated main ligand or the auxiliary ligand. Pure triplet small molecular cyclometalated Ir complex are also briefly introduced. Besides the chemical modification, physical doping of cyclometalated heavy metal complexes as additives into the photovoltaic active layers is finally demonstrated.
The application of heavy-metal complexes in bulk-heterojunction (BHJ) solar cells is a promising new research field which has attracted increasing attention, due to their strong spin-orbit coupling for efficient singlet to triplet intersystem crossing. This review article focuses on recent advances of heavy metal complex containing organic and polymer materials as photovoltaic donors in BHJ solar cells. Platinum-acetylide containing oligomersor and polymers have been firstly illustrated due to the good solubility, square planar structure, as well as the fairly strong Pt-Pt interaction. Then the cyclometalated Pt or Ir complex containing conjugated oligomers and polymers are presented in which the triplet organometallic compounds are embedded into the organic/polymer backbone either through cyclometalated main ligand or the auxiliary ligand. Pure triplet small molecular cyclometalated Ir complex are also briefly introduced. Besides the chemical modification, physical doping of cyclometalated heavy metal complexes as additives into the photovoltaic active layers is finally demonstrated.
2016, 27(8): 1259-1270
doi: 10.1016/j.cclet.2016.06.041
Abstract:
Due to the remarkable electronic, optical, thermal, and mechanical properties, graphene-based materials have shown great potential in a wide range of technique applications. Particularly, the high transparency, conductivity, flexibility, and abundance make graphene materials highly attractive for polymer solar cells (PSCs). Graphene-based materials have been regarded as one promising candidate used in various parts in PSCs not only as electrodes, but also as interfacial layers and active layers with an aim to boost the power conversion efficiency of the devices. In this review, we summarize the recent progress about the design and synthesis of graphene-based materials for efficient PSCs along with the related challenges and future perspectives.
Due to the remarkable electronic, optical, thermal, and mechanical properties, graphene-based materials have shown great potential in a wide range of technique applications. Particularly, the high transparency, conductivity, flexibility, and abundance make graphene materials highly attractive for polymer solar cells (PSCs). Graphene-based materials have been regarded as one promising candidate used in various parts in PSCs not only as electrodes, but also as interfacial layers and active layers with an aim to boost the power conversion efficiency of the devices. In this review, we summarize the recent progress about the design and synthesis of graphene-based materials for efficient PSCs along with the related challenges and future perspectives.
2016, 27(8): 1271-1276
doi: 10.1016/j.cclet.2016.06.015
Abstract:
As an emerging donor building block, naphthodithiophene (NDT) is causing more concerns in the field of organic semiconductors. With the rigid and coplanar molecule structure, NDT will exhibit more application space relying on its own advantage for facilitating the charge carrier transport. In this review article, we have summarized the development progress on the NDT-based donor materials for solution processed organic solar cells. Discussions and comments on those representative NDT type materials about structure and property are also presented.
As an emerging donor building block, naphthodithiophene (NDT) is causing more concerns in the field of organic semiconductors. With the rigid and coplanar molecule structure, NDT will exhibit more application space relying on its own advantage for facilitating the charge carrier transport. In this review article, we have summarized the development progress on the NDT-based donor materials for solution processed organic solar cells. Discussions and comments on those representative NDT type materials about structure and property are also presented.
2016, 27(8): 1277-1282
doi: 10.1016/j.cclet.2016.06.032
Abstract:
Donor-acceptor type copolymers have wide applications in organic field-effect transistors and organic photovoltaic devices. Thieno[3 ,4-c ]pyrrole-4, 6-dione (TPD), as an electron-withdrawing unit, has been widely used in D-A type copolymers recently. Till now, the highest power conversion efficiency and mobility of TPD-based copolymers are over 8% and 1.0 cm2 V-1 s-1 respectively. In this review, the recent progress of TPD-based copolymers in organic solar cells and organic transistors is summarized.
Donor-acceptor type copolymers have wide applications in organic field-effect transistors and organic photovoltaic devices. Thieno[
2016, 27(8): 1283-1292
doi: 10.1016/j.cclet.2016.07.003
Abstract:
Non-fullerene organic solar cells have received increasing attentions in these years, and great progresses have been made since 2013. Among them, aromatic di-amide/imide-containing frameworks have shown promising applications. The outstanding properties of them are highly associated with their unique electronic and structural features, such as strong electron-withdrawing nature, broad absorption in UV-visible region, tunable HOMO/LUMO energy levels, easy modifications, and excellent chemical, thermal and photochemical stabilities. In this review, we give an overview of recent developments of aromatic diamide/imide-containing small molecules used as electron acceptors for organic solar cells.
Non-fullerene organic solar cells have received increasing attentions in these years, and great progresses have been made since 2013. Among them, aromatic di-amide/imide-containing frameworks have shown promising applications. The outstanding properties of them are highly associated with their unique electronic and structural features, such as strong electron-withdrawing nature, broad absorption in UV-visible region, tunable HOMO/LUMO energy levels, easy modifications, and excellent chemical, thermal and photochemical stabilities. In this review, we give an overview of recent developments of aromatic diamide/imide-containing small molecules used as electron acceptors for organic solar cells.
2016, 27(8): 1293-1303
doi: 10.1016/j.cclet.2016.07.004
Abstract:
Organic π-functional molecules are the foundation and basic component of organic optoelectronic devices. For example, for ideal carrier transporting materials, extended π-conjugation and ordered π-π stacking are necessary to enhance the charge mobility and achieve desirable results. As a promising way to convert sunlight into electricity, organometal halide perovskite solar cells (PSCs) have captured a lot of attention due to its predominant merits especially in the aspect of remarkable photovoltaic performance and much potentially low production cost. For conventional planar PSC structure, hole-transporting layer which typically consists of organic π-functional materials plays a key role in suppressing hole-electron pair recombination, promoting charge transporting and ensuring ohmic contact of back electrode. Considering the key roles of HTMs and its soaring progress in recent years, here, we will summarize recent progress in small organic π-functional materials from its diverse functions in PSCs. Besides, aiming to further promote the development of organic π-functional molecules and HTMs, a promising direction toward highly efficient HTMs will also be discussed.
Organic π-functional molecules are the foundation and basic component of organic optoelectronic devices. For example, for ideal carrier transporting materials, extended π-conjugation and ordered π-π stacking are necessary to enhance the charge mobility and achieve desirable results. As a promising way to convert sunlight into electricity, organometal halide perovskite solar cells (PSCs) have captured a lot of attention due to its predominant merits especially in the aspect of remarkable photovoltaic performance and much potentially low production cost. For conventional planar PSC structure, hole-transporting layer which typically consists of organic π-functional materials plays a key role in suppressing hole-electron pair recombination, promoting charge transporting and ensuring ohmic contact of back electrode. Considering the key roles of HTMs and its soaring progress in recent years, here, we will summarize recent progress in small organic π-functional materials from its diverse functions in PSCs. Besides, aiming to further promote the development of organic π-functional molecules and HTMs, a promising direction toward highly efficient HTMs will also be discussed.
2016, 27(8): 1304-1318
doi: 10.1016/j.cclet.2016.07.002
Abstract:
Dye-sensitized solar cells (DSSCs) have attracted significant attention as alternatives to conventional silicon-based solar cells owing to their low-cost production, facile fabrication, excellent stability and high power conversion efficiency (PCE). The dye molecule is one of the key components in DSSCs since it significant influence on the PCE, charge separation, light-harvesting, as well as the device stability. Among various dyes, easily tunable phenothiazine-based dyes hold a large proportion and achieve impressive photovoltaic performances. This class of dyes not only has superiorly non-planar butterfly structure but also possesses excellent electron donating ability and large π conjugated system. This review summarized recent developments in the phenothiazine dyes, including small molecule phenothiazine dyes, polymer phenothiazine dyes and phenothiazine dyes for co-sensitization, especially focused on the developments and design concepts of small molecule phenothiazine dyes, as well as the correlation between molecular structures and the photovoltaic performances.
Dye-sensitized solar cells (DSSCs) have attracted significant attention as alternatives to conventional silicon-based solar cells owing to their low-cost production, facile fabrication, excellent stability and high power conversion efficiency (PCE). The dye molecule is one of the key components in DSSCs since it significant influence on the PCE, charge separation, light-harvesting, as well as the device stability. Among various dyes, easily tunable phenothiazine-based dyes hold a large proportion and achieve impressive photovoltaic performances. This class of dyes not only has superiorly non-planar butterfly structure but also possesses excellent electron donating ability and large π conjugated system. This review summarized recent developments in the phenothiazine dyes, including small molecule phenothiazine dyes, polymer phenothiazine dyes and phenothiazine dyes for co-sensitization, especially focused on the developments and design concepts of small molecule phenothiazine dyes, as well as the correlation between molecular structures and the photovoltaic performances.
2016, 27(8): 1319-1329
doi: 10.1016/j.cclet.2016.06.045
Abstract:
In recent years, organic field-effect transistors (OFETs) with high performance and novel multifunctionalities have attracted considerable attention. Meanwhile, featured with reversible photoisomerization and the corresponding variation in color, chemical/physical properties, photochromic molecules have been applied in sensors, photo-switches and memories. Incorporation of photochromic molecules to blend in the device functional layers or to modify the interfaces of OFETs is common way to build photo-transistors. In this review, we focus on the recent advantages on the study of photoresponsive transistors involving one of three typical photochromic compounds spiropyran, diarylethene and azobenzene. Three main strategies are demonstrated in detail. Firstly, photochromic molecules are doped in active layers or combined with semiconductor structure thus forming photoreversible active layers. Secondly, the modification of dielectric layer/active layer interface is mainly carried out by bilayer dielectric. Thirdly, the photo-isomerization of self-assembled monolayer (SAM) on the electrode/active layer interface can reversibly modulate the work functions and charge injection barrier, result in bifunctional OFETs. All in all, the combination of photochromic molecules and OFETs is an efficient way for the fabrication of organic photoelectric devices. Photoresponsive transistors consisted of photochromic molecules are potential candidate for real applications in the future.
In recent years, organic field-effect transistors (OFETs) with high performance and novel multifunctionalities have attracted considerable attention. Meanwhile, featured with reversible photoisomerization and the corresponding variation in color, chemical/physical properties, photochromic molecules have been applied in sensors, photo-switches and memories. Incorporation of photochromic molecules to blend in the device functional layers or to modify the interfaces of OFETs is common way to build photo-transistors. In this review, we focus on the recent advantages on the study of photoresponsive transistors involving one of three typical photochromic compounds spiropyran, diarylethene and azobenzene. Three main strategies are demonstrated in detail. Firstly, photochromic molecules are doped in active layers or combined with semiconductor structure thus forming photoreversible active layers. Secondly, the modification of dielectric layer/active layer interface is mainly carried out by bilayer dielectric. Thirdly, the photo-isomerization of self-assembled monolayer (SAM) on the electrode/active layer interface can reversibly modulate the work functions and charge injection barrier, result in bifunctional OFETs. All in all, the combination of photochromic molecules and OFETs is an efficient way for the fabrication of organic photoelectric devices. Photoresponsive transistors consisted of photochromic molecules are potential candidate for real applications in the future.
2016, 27(8): 1330-1338
doi: 10.1016/j.cclet.2016.06.023
Abstract:
As a quite ubiquitous phenomenon, crystal polymorph is one of the key issues in the field of organic semiconductors. This review gives a brief summary to the advances on polymorph control of thin film and single crystal of representative organic semiconductors towards high-performance field-effect transistors. Particularly, the relationship between crystal polymporh and charge transport behaviour has been discussed to shed light on the rational preparation of outstanding organic semiconducting materials with desired crystal polymorph.
As a quite ubiquitous phenomenon, crystal polymorph is one of the key issues in the field of organic semiconductors. This review gives a brief summary to the advances on polymorph control of thin film and single crystal of representative organic semiconductors towards high-performance field-effect transistors. Particularly, the relationship between crystal polymporh and charge transport behaviour has been discussed to shed light on the rational preparation of outstanding organic semiconducting materials with desired crystal polymorph.
2016, 27(8): 1339-1344
doi: 10.1016/j.cclet.2016.06.044
Abstract:
The paper summarizes and discusses the recent advances of proteins as functional interlayers in organic field-effect transistors (OFETs). Specific focus is given on the proteins integrated into the device structure, either to act as dielectric materials or to perform as the functional interlayer between the dielectric and the organic semiconductor (OSC). The main emphasis is give to the location and the specific effect of protein layers in the structure of OFETs. Besides, the possibility of amyloid serving as useful building blocks for OFET is discussed.
The paper summarizes and discusses the recent advances of proteins as functional interlayers in organic field-effect transistors (OFETs). Specific focus is given on the proteins integrated into the device structure, either to act as dielectric materials or to perform as the functional interlayer between the dielectric and the organic semiconductor (OSC). The main emphasis is give to the location and the specific effect of protein layers in the structure of OFETs. Besides, the possibility of amyloid serving as useful building blocks for OFET is discussed.
2016, 27(8): 1345-1349
doi: 10.1016/j.cclet.2016.06.030
Abstract:
The emission manners of organic light-emitting diodes (OLEDs) have experienced almost three-decade evolution. In this review, we briefly summarized the emission manners of OLEDs including: (i) emission from singlet exciton; (ii) emission from triplet exciton; (iii) emission from singlet exciton converted from triplet exciton. Then we introduced a new type of OLEDs with the emission from doublet exciton, wherein organic neutral radicals are used as emitters. Due to the spin-allowed transition of doublet excitons, using neutral radicals as emitters is believed to be a new way to break the 25% upper limit of internal quantum efficiency of OLEDs. The progress of emissive stable neutral radicals is also shortly reviewed.
The emission manners of organic light-emitting diodes (OLEDs) have experienced almost three-decade evolution. In this review, we briefly summarized the emission manners of OLEDs including: (i) emission from singlet exciton; (ii) emission from triplet exciton; (iii) emission from singlet exciton converted from triplet exciton. Then we introduced a new type of OLEDs with the emission from doublet exciton, wherein organic neutral radicals are used as emitters. Due to the spin-allowed transition of doublet excitons, using neutral radicals as emitters is believed to be a new way to break the 25% upper limit of internal quantum efficiency of OLEDs. The progress of emissive stable neutral radicals is also shortly reviewed.
2016, 27(8): 1350-1356
doi: 10.1016/j.cclet.2016.05.014
Abstract:
The intimate connection between stacking modes and optoelectronic properties of organic conjugated materials has been discussed from the viewpoints of developing microscopic models and further understanding of their functions and potential applications. In particular, three basal dimer configurations (cofacial configuration, staggered configuration, and crossed configuration) and their respective optical (including radiative and non-radiative) and electrical properties are expatiated in detail. Eventually, we put forward the perspective on achieving the promising laser material that features high fluorescence quantum yield and charge mobility.
The intimate connection between stacking modes and optoelectronic properties of organic conjugated materials has been discussed from the viewpoints of developing microscopic models and further understanding of their functions and potential applications. In particular, three basal dimer configurations (cofacial configuration, staggered configuration, and crossed configuration) and their respective optical (including radiative and non-radiative) and electrical properties are expatiated in detail. Eventually, we put forward the perspective on achieving the promising laser material that features high fluorescence quantum yield and charge mobility.
2016, 27(8): 1357-1366
doi: 10.1016/j.cclet.2016.05.033
Abstract:
Organic photovoltaics and field-effect transistors have attracted considerable attention due to the easy fabrication, low cost, light weight, and flexibility. Unsymmetrical conjugated building blocks are widely utilized for the design of new organic π-functional materials in order to achieve high-performance electronic devices, which has become a hot research topic in recent years. In this review, we summarized some typical organic π-functional materials with regioregular conjugated backbones with unsymmetrical electron-deficiency moieties and focused on the influence of regiochemistry on the final device performance.
Organic photovoltaics and field-effect transistors have attracted considerable attention due to the easy fabrication, low cost, light weight, and flexibility. Unsymmetrical conjugated building blocks are widely utilized for the design of new organic π-functional materials in order to achieve high-performance electronic devices, which has become a hot research topic in recent years. In this review, we summarized some typical organic π-functional materials with regioregular conjugated backbones with unsymmetrical electron-deficiency moieties and focused on the influence of regiochemistry on the final device performance.
2016, 27(8): 1367-1375
doi: 10.1016/j.cclet.2016.06.049
Abstract:
Mechanochromic organic materials are a typical class of stimuli materials that has response to external physical stimuli such as shearing, grinding, and compressing etc. Organic compounds with mechanochromic characters in solid forms have attracted significant attention in the past decades due to their potential applications in sensors and memory devices. Diamond anvil cell is an emerging technology that can provide isotropic pressure in a tiny place. Thus a new stimuli method can be applied in investigating optical variation of mechanochromic materials. In this review, we focus on mechanoluminescence systems that are responsive to isotropic compression under high pressure and summarize the recent advances on organic materials studied by the diamond anvil cell.
Mechanochromic organic materials are a typical class of stimuli materials that has response to external physical stimuli such as shearing, grinding, and compressing etc. Organic compounds with mechanochromic characters in solid forms have attracted significant attention in the past decades due to their potential applications in sensors and memory devices. Diamond anvil cell is an emerging technology that can provide isotropic pressure in a tiny place. Thus a new stimuli method can be applied in investigating optical variation of mechanochromic materials. In this review, we focus on mechanoluminescence systems that are responsive to isotropic compression under high pressure and summarize the recent advances on organic materials studied by the diamond anvil cell.
2016, 27(8): 1376-1382
doi: 10.1016/j.cclet.2016.05.020
Abstract:
Covalent organic frameworks (COFs) represent an emerging class of porous crystalline materials and have recently shown interesting applications from catalysis to optoelectronic devices. In this review, by covering most of the reported work, we summarized the research progress of two-dimensional (2D) porphyrin- and phthalocyanine-based COFs, with highlighting the synthesis of these 2D COFs via various dynamic covalent reactions and emphasizing their potential applications in different areas.
Covalent organic frameworks (COFs) represent an emerging class of porous crystalline materials and have recently shown interesting applications from catalysis to optoelectronic devices. In this review, by covering most of the reported work, we summarized the research progress of two-dimensional (2D) porphyrin- and phthalocyanine-based COFs, with highlighting the synthesis of these 2D COFs via various dynamic covalent reactions and emphasizing their potential applications in different areas.
2016, 27(8): 1383-1394
doi: 10.1016/j.cclet.2016.06.046
Abstract:
Covalent organic frameworks (COFs) as an emerging class of porous materials have achieved remarkable progress in recent years. Their high surface area, low mass densities, highly ordered periodic structures, and ease of functionalization make COFs exhibit superior potential in gas storage and separation, optoelectronic device and catalysis. This mini review gives a brief introduction of COFs and highlights their applications in electronic and optical fields.
Covalent organic frameworks (COFs) as an emerging class of porous materials have achieved remarkable progress in recent years. Their high surface area, low mass densities, highly ordered periodic structures, and ease of functionalization make COFs exhibit superior potential in gas storage and separation, optoelectronic device and catalysis. This mini review gives a brief introduction of COFs and highlights their applications in electronic and optical fields.
2016, 27(8): 1395-1404
doi: 10.1016/j.cclet.2016.07.010
Abstract:
In recent years, as a new class of two-dimensional polymer, covalent organic frameworks (COFs) have attracted intensive attention and developed rapidly. This review provides an overview of a type of COFs which can be utilized as organic semiconductors. Carefully choosing monomers as the building blocks will bestow different types of semiconducting character on COFs. We summarize the p-type, n-type and ambipolar semiconducting COFs and highlight the effects of π-functional building blocks on the photoconductive behaviors of the semiconducting COFs.
In recent years, as a new class of two-dimensional polymer, covalent organic frameworks (COFs) have attracted intensive attention and developed rapidly. This review provides an overview of a type of COFs which can be utilized as organic semiconductors. Carefully choosing monomers as the building blocks will bestow different types of semiconducting character on COFs. We summarize the p-type, n-type and ambipolar semiconducting COFs and highlight the effects of π-functional building blocks on the photoconductive behaviors of the semiconducting COFs.
2016, 27(8): 1405-1411
doi: 10.1016/j.cclet.2016.06.050
Abstract:
The short review discusses a family of amorphous porous organic polymers, conjugated microporous polymer (CMP), which is distinctive in fusion of a large p-electronic conjugation within the topological network platform. The kind of polymers has shown the synthetic variety, the advanced capability and the wide applicability in contrast to the reported analogues. Herein, the significant progress of CMP applications has been summarized to showcase their capability in constructing photo-functional systems.
The short review discusses a family of amorphous porous organic polymers, conjugated microporous polymer (CMP), which is distinctive in fusion of a large p-electronic conjugation within the topological network platform. The kind of polymers has shown the synthetic variety, the advanced capability and the wide applicability in contrast to the reported analogues. Herein, the significant progress of CMP applications has been summarized to showcase their capability in constructing photo-functional systems.
2016, 27(8): 1412-1420
doi: 10.1016/j.cclet.2016.07.011
Abstract:
In recent years, cancer has been one of the leading causes of death in the world. Much effort has been devoted to developing cancer treatments. Photodynamic therapy (PDT) is a noninvasive therapeutic modality by combining the light of a specific wavelength, a photosensitizer (PS) and oxygen, which has been widely applied for the treatment of cancers. However, the application of PDT in clinic is greatly limited due to lack of tumor selectivity and often causing skin photosensitivity. The use of organic nanoparticles (NPs) as an advanced technology in the field of PDT shows a great promise to overcome these shortcomings. Therefore, in this review, we summarize several functional organic NPs as PS carriers that have been developed to enhance the efficacy of PDT against cancers.
In recent years, cancer has been one of the leading causes of death in the world. Much effort has been devoted to developing cancer treatments. Photodynamic therapy (PDT) is a noninvasive therapeutic modality by combining the light of a specific wavelength, a photosensitizer (PS) and oxygen, which has been widely applied for the treatment of cancers. However, the application of PDT in clinic is greatly limited due to lack of tumor selectivity and often causing skin photosensitivity. The use of organic nanoparticles (NPs) as an advanced technology in the field of PDT shows a great promise to overcome these shortcomings. Therefore, in this review, we summarize several functional organic NPs as PS carriers that have been developed to enhance the efficacy of PDT against cancers.
2016, 27(8): 1421-1428
doi: 10.1016/j.cclet.2016.06.027
Abstract:
Organic field-effect transistors are of great importance to electronic devices. With the emergence of various preparation techniques for organic semiconductor materials, the device performance has been improved remarkably. Among all of the organic materials, single crystals are potentially promising for high performances due to high purity and well-ordered molecular arrangement. Based on organic single crystals, alignment and patterning techniques are essential for practical industrial application of electronic devices. In this review, recently developed methods for crystal alignment and patterning are described.
Organic field-effect transistors are of great importance to electronic devices. With the emergence of various preparation techniques for organic semiconductor materials, the device performance has been improved remarkably. Among all of the organic materials, single crystals are potentially promising for high performances due to high purity and well-ordered molecular arrangement. Based on organic single crystals, alignment and patterning techniques are essential for practical industrial application of electronic devices. In this review, recently developed methods for crystal alignment and patterning are described.
2016, 27(8): 1453-1463
doi: 10.1016/j.cclet.2016.05.030
Abstract:
This paper summarizes our recent works on theoretical modelling of molecular packing and electronic processes in small-molecule organic solar cells. Firstly, we used quantum-chemical calculations to illustrate exciton-dissociation and charge-recombination processes at the DTDCTB/C60 interface and particularly emphasized the major role of hot charge-transfer states in the exciton-dissociation processes. Then, we systematically analyzed the influence of DTDCTB surfaces with different features on the vacuum vapor deposition growth and packing morphologies of C60 via atomistic molecular dynamics simulations, and found that the formation of crystalline fullerene is the result of an integrated impact of stability, landscape, and molecular orientation of the substrate surfaces. Also, we investigated the impact of different film-processing conditions, such as solvent evaporation rates and thermal annealing, on molecular packing configurations in a neat small-molecule donor material, DPP(TBFu)2, and discussed the correlation between charge mobility and molecular packing via atomistic simulations in combination with electronic-structure calculations and kinetic Monte Carlo simulations.
This paper summarizes our recent works on theoretical modelling of molecular packing and electronic processes in small-molecule organic solar cells. Firstly, we used quantum-chemical calculations to illustrate exciton-dissociation and charge-recombination processes at the DTDCTB/C60 interface and particularly emphasized the major role of hot charge-transfer states in the exciton-dissociation processes. Then, we systematically analyzed the influence of DTDCTB surfaces with different features on the vacuum vapor deposition growth and packing morphologies of C60 via atomistic molecular dynamics simulations, and found that the formation of crystalline fullerene is the result of an integrated impact of stability, landscape, and molecular orientation of the substrate surfaces. Also, we investigated the impact of different film-processing conditions, such as solvent evaporation rates and thermal annealing, on molecular packing configurations in a neat small-molecule donor material, DPP(TBFu)2, and discussed the correlation between charge mobility and molecular packing via atomistic simulations in combination with electronic-structure calculations and kinetic Monte Carlo simulations.
2016, 27(8): 1429-1436
doi: 10.1016/j.cclet.2016.05.019
Abstract:
The detection of peroxide explosives (PEs) has attracted considerable attention all over the world in global security owing to their simple preparation, poor chemical stability and easy decomposition. In recent years, great efforts have been devoted to developing organic fluorescence sensors for detecting the PEs because of their fast response, high sensitivity and high selectivity. In this short review, we firstly discuss the sensing mechanisms for fluorescence based the PEs detection. Next, we reviewed recent progress of PE probes in the nearly 5 years and the design strategies of the material structures to enhance the sensitivity or selectivity, such as conjugated polymers and assembled nanoparticles.
The detection of peroxide explosives (PEs) has attracted considerable attention all over the world in global security owing to their simple preparation, poor chemical stability and easy decomposition. In recent years, great efforts have been devoted to developing organic fluorescence sensors for detecting the PEs because of their fast response, high sensitivity and high selectivity. In this short review, we firstly discuss the sensing mechanisms for fluorescence based the PEs detection. Next, we reviewed recent progress of PE probes in the nearly 5 years and the design strategies of the material structures to enhance the sensitivity or selectivity, such as conjugated polymers and assembled nanoparticles.
2016, 27(8): 1437-1444
doi: 10.1016/j.cclet.2016.06.048
Abstract:
Three-dimensional graphene/conducting polymer (3DGCP) composites have received significant attention in recent years due to their unique structures and promising applications in energy storage. With the structural diversity of graphene and π-functional conducting polymers via rich chemical routes, a number of 3DGCP composites with novel structures and attractive performance have been developed. Particularly, the hierarchical porosity, the interactions between graphene and conducting polymers as well as the their synergetic effects within 3DGCP composites can be well combined and elaborated by various synthetic methods, which made 3DGCP composites show unique electrochemical properties and significantly improved performance in energy storage fields compared to other graphenebased composites. In this short review, we present recent advances in 3DGCP composites in developing effective strategies to prepare 3DGCP composites and exploring them as a unique platform for supercapacitors with unprecedented performance. The challenges and future opportunities are also discussed for promotion of further study.
Three-dimensional graphene/conducting polymer (3DGCP) composites have received significant attention in recent years due to their unique structures and promising applications in energy storage. With the structural diversity of graphene and π-functional conducting polymers via rich chemical routes, a number of 3DGCP composites with novel structures and attractive performance have been developed. Particularly, the hierarchical porosity, the interactions between graphene and conducting polymers as well as the their synergetic effects within 3DGCP composites can be well combined and elaborated by various synthetic methods, which made 3DGCP composites show unique electrochemical properties and significantly improved performance in energy storage fields compared to other graphenebased composites. In this short review, we present recent advances in 3DGCP composites in developing effective strategies to prepare 3DGCP composites and exploring them as a unique platform for supercapacitors with unprecedented performance. The challenges and future opportunities are also discussed for promotion of further study.
2016, 27(8): 1445-1452
doi: 10.1016/j.cclet.2016.07.017
Abstract:
Thermally activated delayed fluorescence (TADF) emitters are primarily comprised of intramolecular charge-transfer (ICT) molecules with small energy difference between the lowest singlet and triplet excited states. They lend extremely favorable electroluminescent performance to organic light-emitting diodes (OLEDs). This paper summarizes relevant issues and research efforts in the theoretical prediction of singlet- and triplet-transition energies of ICT molecules via time-dependent density functional theory (TDDFT). The successful application of the descriptor-based optimal Hartree-Fock percentage method and the optimally tuned range-separated functional to many TADF systems represent an interesting approach to the exact prediction of the complex excited-state molecular dynamics within TDDFT.
Thermally activated delayed fluorescence (TADF) emitters are primarily comprised of intramolecular charge-transfer (ICT) molecules with small energy difference between the lowest singlet and triplet excited states. They lend extremely favorable electroluminescent performance to organic light-emitting diodes (OLEDs). This paper summarizes relevant issues and research efforts in the theoretical prediction of singlet- and triplet-transition energies of ICT molecules via time-dependent density functional theory (TDDFT). The successful application of the descriptor-based optimal Hartree-Fock percentage method and the optimally tuned range-separated functional to many TADF systems represent an interesting approach to the exact prediction of the complex excited-state molecular dynamics within TDDFT.
