The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Wei Huang - One of the best experts on this subject based on the ideXlab platform.
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the Inductive Effect of electron withdrawing trifluoromethyl for thermally activated delayed fluorescence tunable emission from tetra to penta carbazole in solution processed blue oleds
Chemical Communications, 2015Co-Authors: Jia Hu, Fangfang Wang, Chao Zheng, Xinwen Zhang, Wei HuangAbstract:The non-conjugated Inductive Effect of trifluoromethyl (CF3) was found to be a new acceptor instead of other conjugated moieties. Two blue emissive compounds, 4CzCF3Ph and 5CzCF3Ph, were synthesized using a simple catalyst-free C–N coupling reaction. Solution-processed TADF devices based on the 5CzCF3Ph dopant exhibit significantly higher efficiency (11.8 cd A−1, 5.2%) than 4CzCF3Ph (1.03 cd A−1, 0.67%) due to the smaller ΔEST value for efficient RISC.
Hui Xu - One of the best experts on this subject based on the ideXlab platform.
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a red thermally activated delayed fluorescence emitter employing dipyridophenazine with a gradient multi Inductive Effect to improve radiation efficiency
Journal of Materials Chemistry C, 2019Co-Authors: Huiqin Wang, Chunbo Duan, Guanying Chen, Bingjie Zhao, Chenxi Zhao, Jing Zhang, Zhe Li, Xinyu Wang, Hui XuAbstract:Developing efficient red thermally activated delayed fluorescence (TADF) emitters is a real challenge due to the serious nonradiation of their low-band-gap singlet charge transfer state. Dipyridophenazine (DPPZ) (weak electron-withdrawing pyridines fused with strong electron-withdrawing phenazine) is used as an acceptor to overcome this issue. The gradient multi-Inductive Effect of different heterocyclic units simultaneously enhances the intramolecular charge transfer for red emission of the TADF molecule oTPA-DPPZ, and facilitates the radiative transition of its singlet charge transfer state by increasing frontier molecular orbital overlap on the electron-deficient pyrazine moiety. The 10-fold increased oscillator strength of its singlet transition results in its excellent photoluminescence and electroluminescence quantum efficiencies of ∼75% and ∼19%, accompanied by red emission peaked around 600 nm.
Huiqin Wang - One of the best experts on this subject based on the ideXlab platform.
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a red thermally activated delayed fluorescence emitter employing dipyridophenazine with a gradient multi Inductive Effect to improve radiation efficiency
Journal of Materials Chemistry C, 2019Co-Authors: Huiqin Wang, Chunbo Duan, Guanying Chen, Bingjie Zhao, Chenxi Zhao, Jing Zhang, Zhe Li, Xinyu Wang, Hui XuAbstract:Developing efficient red thermally activated delayed fluorescence (TADF) emitters is a real challenge due to the serious nonradiation of their low-band-gap singlet charge transfer state. Dipyridophenazine (DPPZ) (weak electron-withdrawing pyridines fused with strong electron-withdrawing phenazine) is used as an acceptor to overcome this issue. The gradient multi-Inductive Effect of different heterocyclic units simultaneously enhances the intramolecular charge transfer for red emission of the TADF molecule oTPA-DPPZ, and facilitates the radiative transition of its singlet charge transfer state by increasing frontier molecular orbital overlap on the electron-deficient pyrazine moiety. The 10-fold increased oscillator strength of its singlet transition results in its excellent photoluminescence and electroluminescence quantum efficiencies of ∼75% and ∼19%, accompanied by red emission peaked around 600 nm.
Jiahua Zhang - One of the best experts on this subject based on the ideXlab platform.
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the Inductive Effect of neighboring cations in tuning luminescence properties of the solid solution phosphors
Inorganic Chemistry, 2017Co-Authors: Wenge Xiao, Dan Wu, Liangliang Zhang, Xia Zhang, Ligong Zhang, Xuewei Ba, Jiahua ZhangAbstract:Forming solid solutions through cation substitution is an efficient way to improve the luminescence properties of Ce3+ or Eu2+ activated phosphors and even to develop new ones, which is badly needed for phosphor-converted white LEDs. Here, we report new color tunable solid solution phosphors based on Eu2+ activated K2Al2B2O7 as a typical case to demonstrate that, besides crystal field splitting of 5d levels, centroid shift and Stokes shift can be dominant in tuning excitation and emission spectra as well as thermal stability of solid solution phosphors, both of which were previously considered to be negligible. Moreover, a general model involving the Inductive Effect of neighboring cations is proposed to explain the obvious variations in centroid shift and Stokes shift with cation substitution. Our work is propitious for the construction of more reasonable structure–property relations and thus offers theoretical guidance for designing solid solution phosphors.
Jia Hu - One of the best experts on this subject based on the ideXlab platform.
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the Inductive Effect of electron withdrawing trifluoromethyl for thermally activated delayed fluorescence tunable emission from tetra to penta carbazole in solution processed blue oleds
Chemical Communications, 2015Co-Authors: Jia Hu, Fangfang Wang, Chao Zheng, Xinwen Zhang, Wei HuangAbstract:The non-conjugated Inductive Effect of trifluoromethyl (CF3) was found to be a new acceptor instead of other conjugated moieties. Two blue emissive compounds, 4CzCF3Ph and 5CzCF3Ph, were synthesized using a simple catalyst-free C–N coupling reaction. Solution-processed TADF devices based on the 5CzCF3Ph dopant exhibit significantly higher efficiency (11.8 cd A−1, 5.2%) than 4CzCF3Ph (1.03 cd A−1, 0.67%) due to the smaller ΔEST value for efficient RISC.