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

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270/290/330nm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AlGaN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。

270/290/330 nm AlGaN-based Deep Ultraviolet Light-emitting Diodes with Different Al Content in Quantum Wells and Barriers

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.