渐变型量子阱垒层厚度对GaN基双波长发光二极管发光特性调控的研究

采用软件理论分析的方法对渐变型量子阱垒层厚度的InGaN双波长发光二极(LED)的载流子浓度分布、 能带结构、自发发射谱、内量子效率、发光功率及溢出电子流等进行研究.分析结果表明, 增大量子阱垒层厚度会影响空穴在各量子阱的注入情况, 对双波长LED各量子阱中空穴浓度分布的 均衡性及双波长发光光谱的调控起到一定作用,但会导致内量子效率严重下降; 而当以特定的方式从n电极到p电极方向递减渐变量子阱垒层厚度时, 活性层量子阱的溢出电子流 得到有效的控制, 双发光峰强度达到基本一致, 同时芯片的内量子效率下降得到了有效控制, 且具备大驱动电流下较好的发光特性.

The investigation of performance improvement of GaN-based dual-wavelength light-emitting diodes with various thickness of quantum barriers

The electrical and optical characteristics of GaN-based dual-wavelength light-emitting diodes (LEDs) with the specific design of various thick barriers are investigated numerically. The simulation results show that the thickness of barrier plays a regulatory role in emission spectrum of the dual-wavelength LED. The internal quantum efficiency droop is improved and the two peaks of spectrum become uniform due to the thickness of barriers gradually decreasing from the n-side to the p-side in a specific way. The balanced distribution of carrier concentration and the enhancement of electron confinement could be the major physical mechanism behind these improvements. It is also shown that the better optical performance is achieved at the large current injection level.