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IN
Journal article
Efficient blue organic light-emitting device based on N,N di (naphth2yl)N, N diphenyl benzidine with an exciton confining structure
Yoga Divayana Sun Xiaowei Chen Baijun G. Q. Lo C. Y. Jiang K. R. Sarma
Volume : 89 Nomor : 17 Published : 2017, October
Applied Physics Letters
Abstrak
Ablue organic light-emitting device with improved ef?ciency and excellent color purity is reported Commission Internationale de’l Eclairage coordinates of x=0.1659 and y=0.0772 at 5 V, where N, N-dinaphth-2-yl-N, N-diphenyl-benzidine NPB, a traditional hole-transporting layer, was used as the emission layer. A signi?cant increase in ef?ciency was achieved by con?ning the excitons within the NPB layer by two wide-band-gap hole-blocking layers sandwiching the NPB layer. This structure also increases the direct exciton formation at the NPB layer by promoting electrons to cross the NPB layer, responsible for further ef?ciency improvement. Optimized structure showed an external quantum ef?ciency of 1.38%, which accounts for a 25% increase compared to a standard device.