PANG Hong-qi, YUAN Yong-bo, ZHOU Yun-fei, LIAN Jia-rong, CAO Ling-fang, ZHANG Jie, LIU Peng-yi, ZHOU Xiang. Mixed Organic Thin Films for Organic Light-emitting Diodes[J]. Chinese Journal of Luminescence, 2006,27(1): 91-94
PANG Hong-qi, YUAN Yong-bo, ZHOU Yun-fei, LIAN Jia-rong, CAO Ling-fang, ZHANG Jie, LIU Peng-yi, ZHOU Xiang. Mixed Organic Thin Films for Organic Light-emitting Diodes[J]. Chinese Journal of Luminescence, 2006,27(1): 91-94DOI:
Mixed Organic Thin Films for Organic Light-emitting Diodes
The most common used structure of organic light-emitting diodes is the double layer heterojunction structure. By softening the high local electric field and partly eliminating the non-radiative recombination traps at the heterojunction interface
OLEDs with bipolar transport/emitting layer (BTEL) showed improved stability. However
the detail mechanisms of this structure are still undefined. The performance of OLEDs with uniformly mixed organic layer
which was formed by co-evaporating a hole transport material TPD
and an electron transport/emissive material Alq
3
was studied. We observed that the performances of OLEDs with uniformly mixed layer were strongly dependent on the thickness of the mixed-layer
and there exists an optimized thickness of mixed layer. The devices with 5 nm(thickness) mixed layer showed improved lifetime and current efficiency
while the devices with 10 nm or 20 nm(thickness) mixed layers demonstrated similar performance compared to the heterojunction devices. The single layer devices with 100 nm totally mixed layer exhibited a very poor efficiency and stability. A primary discussion on the results was given.
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