InGaN绿光LED的量子阱结构具有较高的In含量, InN与GaN之间较大的晶格失配度使得该结构的稳定性下降。由于量子阱结构生长完成之后的p型GaN的生长温度要远高于量子阱结构生长温度, 因此, p型GaN的生长过程对多量子阱质量有重大影响。论文探讨了p型GaN的生长温度与厚度对绿光LED的材料结构及器件性能的影响。研究发现, p-GaN过高的生长温度和过大的厚度都能加剧多量子阱结构中In组分的波动, 使得发光峰宽化, 同时降低绿光量子阱的发光效率。论文据此提出了优化的p型GaN生长温度与厚度, 探讨了量子阱保护层对InGaN绿光LED性能的影响, 该结构有利于增强绿光LED发光波长的稳定性。

The high fraction of indium (In) in the multi-quantum wells (MQWs) and the large lattice mismatch between InN and GaN dramatically decrease the stability of InGaN-based green light emitting diodes (LEDs). Because the growth temperature of p-GaN is much higher than that of MQWs, the growth of p-GaN will impact the quality of MQWs greatly. In this work, it is focused on the influence of the growth temperature and the thickness of p-GaN on the performance of green LEDs, and it is revealed that too high growth temperature or thickness will have negative impact on the stability of In fraction in MQWs, which results in the broadening of emission peak and the reduction in luminous efficiency. Accordingly, the optimized growth temperature and thickness are proposed. Furthermore, the influence of MQWs protection layer on green LEDs performance is discussed and it is found that this protection layer is beneficial to the stability of the emission wavelength of green LEDs.