Au generation centres doped n(+)-Si: hole-injection adjustable anode for efficient organic light emission

An organic light-emitting diode (OLED) with an n-Si-anode usually has an efficiency evidently lower than the OLED with the same structure with a p-Si-anode due to insufficient hole injection from the n-Si anode compared with the p-Si-anode. In this study, we find that introducing Au as generation centres with a suitable concentration into the n(+)-Si anode can enhance hole injection to match electron injection and then considerably promote the power efficiency. With optimizing Au generation centre concentration in the n(+)-Si anode, the OLED with a structure of n(+)-Si: Au/NPB/AlQ/Sm/Au reaches a highest power efficiency of 1.0 lm W(-1), evidently higher than the reported highest power efficiency of 0.2 lm W(-1) for its p-Si-anode counterpart. Furthermore, when the electron injection is enhanced by adopting BPhen: Cs(2)CO(3) partly instead of AlQ as the electron transport material, and the Au generation centre concentration in the n(+)-Si anode is promoted correspondingly, then a highest power efficiency of 1.8 lm W(-1) is reached. The role of Au generation centres in the n(+)-Si anode is discussed.Physics, AppliedSCI(E)EI4ARTICLE15null4