Compared to red and green organic light-emitting diodes(OLEDs),blue OLEDs are still the bottleneck due to the lack of efficient emitters with simultaneous high exciton utilization efficiency(EUE)and short excited-stat...Compared to red and green organic light-emitting diodes(OLEDs),blue OLEDs are still the bottleneck due to the lack of efficient emitters with simultaneous high exciton utilization efficiency(EUE)and short excited-state lifetime.Different from the fluorescence,phosphorescence,thermally activated delayed fluorescence(TADF),and organic radical materials traditionally used in OLEDs,we demonstrate herein a new type of emitter,cerium(Ⅲ)complex Ce-1 with spin-allowed and parity-allowed d-f transition of the centre Ce^(3+) ion.The compound exhibits a high EUE up to 100% in OLEDs and a short excited-state lifetime of 42 ns,which is considerably faster than that achieved in efficient phosphorescence and TADF emitters.The optimized OLEDs show an average maximum external quantum efficiency(EQE)of 12.4% and Commission Internationale de L’Eclairage(CIE)coordinates of(0.146,0.078).展开更多
Understanding excitonic processes at organic heterojunctions is crucial for development of organic semiconductor devices. This article reviews recent research on excitonic physics that involve intermolecular charge tr...Understanding excitonic processes at organic heterojunctions is crucial for development of organic semiconductor devices. This article reviews recent research on excitonic physics that involve intermolecular charge transfer （CT） excitons, and progress on understanding relationships between various interface energy levels and key parameters governing various competing interface excitonic processes. These interface excitonic processes include radiative exciplex emission, nonradiative recombination, Auger electron emission, and CT exciton dissociation. This article also reviews various device applications involving interface CT excitons, such as organic light-emitting diodes （OLEDs）, organic photovoltaic cells, organic rectifying diodes, and ultralow-voltage Auger OLEDs.展开更多
基金the financial support from the National Key R&D Programme of China(Nos.2017YFA0205100,2016YFB0401001)the Beijing Natural Science Foundation(2202015)+1 种基金financial support from the China Postdoctoral Science Foundation(2018M641065)supported by the high-performance computing platform of Peking University.
文摘Compared to red and green organic light-emitting diodes(OLEDs),blue OLEDs are still the bottleneck due to the lack of efficient emitters with simultaneous high exciton utilization efficiency(EUE)and short excited-state lifetime.Different from the fluorescence,phosphorescence,thermally activated delayed fluorescence(TADF),and organic radical materials traditionally used in OLEDs,we demonstrate herein a new type of emitter,cerium(Ⅲ)complex Ce-1 with spin-allowed and parity-allowed d-f transition of the centre Ce^(3+) ion.The compound exhibits a high EUE up to 100% in OLEDs and a short excited-state lifetime of 42 ns,which is considerably faster than that achieved in efficient phosphorescence and TADF emitters.The optimized OLEDs show an average maximum external quantum efficiency(EQE)of 12.4% and Commission Internationale de L’Eclairage(CIE)coordinates of(0.146,0.078).
基金supported by the National Natural Science Foundation of China(Grant No.U1402273)the Natural Science and Engineering Research Council of Canada
文摘Understanding excitonic processes at organic heterojunctions is crucial for development of organic semiconductor devices. This article reviews recent research on excitonic physics that involve intermolecular charge transfer （CT） excitons, and progress on understanding relationships between various interface energy levels and key parameters governing various competing interface excitonic processes. These interface excitonic processes include radiative exciplex emission, nonradiative recombination, Auger electron emission, and CT exciton dissociation. This article also reviews various device applications involving interface CT excitons, such as organic light-emitting diodes （OLEDs）, organic photovoltaic cells, organic rectifying diodes, and ultralow-voltage Auger OLEDs.
