量子阱层和垒层具有不同 Al 组分的270/290/330 nm AlGaN 基深紫外 LED 光电性能

摘要

The optical and electrical properties of 270 / 290 / 330 nm AlGaN-based deep ultraviolet (UV) light-emitting diodes (LEDs) with different Al content in quantum wells and barriers were in-vestigated systematically. Based on the experimental and numerical study, It is observed that the UV LEDs with longer wavelength and lower Al composition in AlGaN multiple quantum wells (MQWs) possess less dislocation density, higher light output power and internal quantum efficiency. The large ideality factors calculated from I-V curves and simulated energy band profiles indicate that the cur-rent in the deep UV LEDs with high Al content is dominated by tunneling mechanism, which is at-tribute to the resulting potential drop in the active region caused by large polarization field in AlGaN MQWs.%为了研究 AlGaN 量子阱层和垒层中 Al 组分不同对 AlGaN 基深紫外发光二极管(LED)光电性能的影响,本文利用 MOCVD 生长、光刻和干法刻蚀工艺制备了 AlGaN 量子阱层和垒层具有不同 Al 组分的270／290／330 nm 深紫外 LED,通过实验和数值模拟计算方法发现,量子阱层和垒层中具有低 Al 组分紫外 LED 的 Al-GaN 材料具有较低的位错密度、较高的光输出功率和外量子效率。通过电流-电压(I-V)曲线拟合出的较大的理想因子(>3.5)和能带结构图表明,AlGaN 深紫外 LED 的电流产生是隧穿机制占据主导作用,这是因为高Al 组分 AlGaN 量子阱中强极化场造成了有源层区域较大的能带弯曲和电势降。