In组分渐变提高InGaN/GaN多量子阱发光二极管发光性能

利用金属有机物化学气相沉积系统在蓝宝石衬底上通过有源层的变温生长,得到In组分渐变的量子阱结构,从而获得具有三角形能带结构的InGaN/GaN多量子阱发光二极管(LED)(简称三角形量子阱结构LED).变温光致发光谱结果表明,相对于传统具有方形能带结构的量子阱LED(简称方形量子阱结构LED),三角形量子阱结构有效提高了量子阱中电子和空穴波函数的空间交叠,从而增加了LED的内量子效率;电致发光谱结果表明,三角形量子阱结构LED器件与传统结构LED器件相比,明显改善了发光峰值波长随着电流的蓝移现象.通过以上

Luminous performance improvement of InGaN/GaN light-emitting diodes by modulating In content in well layers

InGaN/GaN triangular shaped multiple quantum wells (MQWs) grown on sapphire substrate were adopted as an active layer of light-emitting diodes (LEDs) by modulating In content in well layers. The temperature dependence of the normalized integrated photoluminescence (PL) intensity showed that the overlap of the electron and hole wave-functions of the LEDs with triangular shaped MQW is much higher than that of the LEDs with conventional rectangular MQW structures, which improves the internal quantum efficiency (IQE) to a certain degree. On the other hand, it was found that the blue shift of the peak energy as a function of injection current is improved for the device with triangular shaped MQW structure from the electroluminescence (EL) spectra of the two series devices. The comparison above indicates that the triangular MQW LEDs are more efficient and more stable.