InGaN/GaN MQW双波长LED的MOCVD生长

Dual-wavelength InGaN/GaN MQW LEDs Grown by MOCVD

利用金属有机物化学气相淀积(MOCVD)系统生长了InGaN/GaN多量子阱双波长发光二极管(LED)。发现在20 mA正向注入电流下空穴很难输运过蓝光和绿光量子阱间的垒层,这是混合量子阱有源区获得双波长发光的主要障碍。通过掺入一定量的In来降低蓝光和绿光量子阱之间的垒层的势垒高度,增加注入到离p-GaN层较远的绿光有源区的空穴浓度,从而改变蓝光和绿光发光峰的强度比。研究了蓝光和绿光量子阱间垒层In组分对双波长LED的发光性质的影响。此外,研究了双波长LED发光特性随注入电流的变化。

Dual-wavelength light emitting diodes（LEDs） with InGaN/GaN multi-quantum wells（MQW） active region were grown by metalorganic chemical vapor deposition（MOCVD）. It was found that the holes were difficult to transport over the GaN potential barrier located between the blue QW and the green QWs at the forward current of 20 mA, which was the main obstacle to obtain the dual-wavelength emission for the mixed QWs active region. Band gap of barrier layer between blue quantum well and green quantum wells could be changed by incorporating a certain percent of In, which increased the injection of the hole concentration of green light active region within a long distance of the p-GaN layer and changed the emission intensity ratio of green and blue peak. The effects of In content in the barrier layer between the blue QW and the green QWs on the emission intensity of individual kinds of QW were presented. Moreover, the emission characteristic of dual wavelength LEDs dependent on injection current is examined.