ZnO纳米阵列增强大功率蓝光LED出光效率的研究

摘要

采用低成本的化学溶液法在大功率GaN基蓝光LED芯片上生长ZnO纳米阵列,以提高LED芯片的出光效率.通过改变生长溶液中氨水及锌离子浓度实现对纳米阵列结构形貌的可控性,进而得到不同形貌的ZnO纳米阵列.在此基础上,进一步研究纳米结构形貌对LED芯片出光性能的影响,探讨纳米结构增强LED芯片发光效率的机理.结果表明,较高密度、锥形形貌的ZnO纳米阵列更有利于增强LED芯片的出光效率.在优化的实验条件下,表面沉积ZnO纳米阵列的LED芯片比普通LED的出光效率高出60％以上,并且纳米阵列不影响LED器件的电学性能和发光稳定性.%ZnO nano-arrays were grown on high power GaN blue LED chip by low-cost chemical solution methods, which aimed to enhance the light extraction efficiency of LED chip. Various morphology was achieved by adjusting the concentration of ammonia and Zn2+ in the growth solution. With different growth solution, ZnO nano-arrays exhibited different morphologies and densities. The effect of nano-array morphology on the light extraction performance of the ZnO nano-array coated LED chip were studied. The mechanism of light extraction efficiency enhancement by nano-arrays was also discussed based on the experimental results. The result shows that ZnO nano-arrays with higher density and cone-shaped morphology are favorable for the improvement of light extraction in LED chip. ZnO nano-arrays grown at the optimum conditions can enhance the light extraction of LED chip by more than 60%. Meanwhile, ZnO nano-arrays have no significant effect on the electrical properties and electroluminescence stability of LED chip.