Al组分三角形渐变P-EBL结构AlGaN基DUV LED数值分析

Numerical Analysis of AlGaN-Based DUV LED With Al Composition Triangular Gradient P-EBL Structure

效率陡降严重影响AlGaN基深紫外发光二极管(DUV LED)的输出性能,也是近年来DUV LED的一个瓶颈性问题。对常规电子阻挡层(P-EBL)和Al组分三角形渐变P-EBL两种结构DUV LED进行了数值分析。研究了能带、电子电流、空穴浓度、电场、内量子效率、输出功率和自发辐射光谱的分布特性。模拟结果表明,在260 mA电流注入时,相比常规PEBL结构,Al组分三角形渐变P-EBL结构DUV LED的效率陡降减小了5.85%,改善了DUV LED输出性能。根据数值模拟和分析,器件输出性能改善的原因是Al组分三角形渐变P-EBL结构提高导带势垒高度和增强空穴在P型区域获得的动能,从而减小电子泄漏,并提高了空穴注入效率。

The steep drop in efficiency seriously affects the output performance of AlGaN-based deep ultraviolet lightemitting diodes(DUV LEDs),and is also a bottleneck problem for DUV LEDs in recent years. DUV LEDs with conventional electron blocking layer(P-EBL)and Al composition triangular graded P-EBL are investigated numerically in this paper. The distribution characteristics of energy band,electron current,hole concentration,electric field,internal quantum efficiency,output power and spontaneous emission spectrum are investigated. The simulation results show that when 260 m A current is injected,compared with the conventional P-EBL structure,the efficiency drop of the Al composition triangular graded P-EBL structure DUV LED is reduced by 5.85%,which improves the output performance of the DUV LED. Based on the numerical simulation and analysis,these improvements on the device characteristics are attributed to the remarkable improvement of the electron leakage and hole injection efficiency,which results from the higher effective conduction band barrier height for limitting electrons,and the higher kinetic energy for hole transportation in the Pside.