High efficient yellow organic light emitting diodes （OLEDs） based on exciplex were reported. The exciplex was formed by 4, 4＇, 4″-tris β-methylphenyl （phenyi） amino]-triphenylamine （m-MTDATA） and 4, 7- diphen...High efficient yellow organic light emitting diodes （OLEDs） based on exciplex were reported. The exciplex was formed by 4, 4＇, 4″-tris β-methylphenyl （phenyi） amino]-triphenylamine （m-MTDATA） and 4, 7- diphenyl-1, 10-phenanthroline （BPhen）. The resulting yellow OLEDs exhibited an external quantum efficiency of over 7%, which is attributed to the effective energy back transfer from exciplex triplet state to exciplex singlet state. The maximum power efficiency of 25 lm/W was achieved. Doping a yellow phosphor Ir（bt）2（acac） into m-MTDATA： BPhen blend, a high efficiency device was achieved with a turn-on voltage of 2.1 V, maximum power efficiency and external quantum efficiency of 86.1 lm/W and 20.7%, respectively.展开更多
In this work, transient electroluminescence （EL） （brightness-voltage waveform curve） was utilized to investigate the working mechanism of alternating-current biased organic light-emitting diodes （AC-OLEDs）. In l...In this work, transient electroluminescence （EL） （brightness-voltage waveform curve） was utilized to investigate the working mechanism of alternating-current biased organic light-emitting diodes （AC-OLEDs）. In lower frequency domain, injection potential barrier was the dominant effect to determine the luminescence intensity; with increased frequency, the influence of capacitance effect becomes dominant, which can be confirmed according to the investigations on stable EL of the AC-OLEDs. The results indicate that transient and stable EL can agree with each other perfectly. Besides, the stable EL reveals that the thinner device can take more effective capacitance effect.展开更多
基金Acknowledgements We sincerely thank Y. Gu, C. L. Yang and H. Xu for their careful testing of the samples. The authors gratefully acknowledge the National Natural Science Foundation of China （Grant Nos. 51333007 and 50973104）, the National Basic Research Program of China （No. 2013CB834805）, the Foundation of Jilin Research Council （Nos.2012ZDGG001, 20130206003GX and 201105028）, and Chinese Academy of Sciences Instrument Project （No. YZ201103） for the support of this research.
文摘High efficient yellow organic light emitting diodes （OLEDs） based on exciplex were reported. The exciplex was formed by 4, 4＇, 4″-tris β-methylphenyl （phenyi） amino]-triphenylamine （m-MTDATA） and 4, 7- diphenyl-1, 10-phenanthroline （BPhen）. The resulting yellow OLEDs exhibited an external quantum efficiency of over 7%, which is attributed to the effective energy back transfer from exciplex triplet state to exciplex singlet state. The maximum power efficiency of 25 lm/W was achieved. Doping a yellow phosphor Ir（bt）2（acac） into m-MTDATA： BPhen blend, a high efficiency device was achieved with a turn-on voltage of 2.1 V, maximum power efficiency and external quantum efficiency of 86.1 lm/W and 20.7%, respectively.
文摘In this work, transient electroluminescence （EL） （brightness-voltage waveform curve） was utilized to investigate the working mechanism of alternating-current biased organic light-emitting diodes （AC-OLEDs）. In lower frequency domain, injection potential barrier was the dominant effect to determine the luminescence intensity; with increased frequency, the influence of capacitance effect becomes dominant, which can be confirmed according to the investigations on stable EL of the AC-OLEDs. The results indicate that transient and stable EL can agree with each other perfectly. Besides, the stable EL reveals that the thinner device can take more effective capacitance effect.
