AZO薄膜用于GaN基LED透明电极的性能研究

摘要

采用脉冲激光沉积法制备了Al掺杂ZnO(AZO)薄膜,研究了不同沉积氧压下薄膜的光电性能.当沉积压强为0.1 Pa时,AZO薄膜光电性能最优.将该薄膜用于GaN基LED透明电极作为电流扩展层,在20 mA正向电流下观察到了520 nm处很强的芯片发光峰,但芯片工作电压较高,约为10V,芯片亮度随正向电流的增大而增强.二次离子质谱测试表明,AZO薄膜与GaN层界面处两种材料导电性能的变化以及钝化层的形成是导致芯片工作电压偏高的原因.%Al-doped ZnO (AZO) thin films were prepared by pulsed laser deposition under different oxygen pressures.AZO films with highly transparent conductive properties were obtained at 0.1 Pa.AZO films were used on GaN-based light-emitting diodes (LEDs) as transparent contact layers.At a forward current of 20 mA,the 520 nm electroluminescence peak was evidently observed,with a high working voltage of 10 V.The brightness of the chip was enhanced as the forward current increased.Secondary ion mass spectra revealed that the high working voltage of the LED might be triggered by the change of material conductivity and the passivation layer formed at the AZO/GaN interface.