具有三角形InGaN/GaN多量子阱的高内量子效率的蓝光LED(英文)

对InGaN量子阱LED的内量子效率进行了优化研究。分别对发光光谱、量子阱中的载流子浓度、能带分布、静电场和内量子效应进行了理论分析。对具有不同量子阱数量的InGaN/GaN LED进行了理论数值比对研究。研究结果表明,对于传统结构的LED而言,2个量子阱的结构相对于5个和7个量子阱具有更好的光学性能。同时还研究了具有三角形量子阱结构的LED,研究结果显示,三角形多量子阱结构具有较高的电致发光强度、更高的内量子效率和更好的发光效率,所有的优点都归因于较高的电子-空穴波函数重叠率和低的Stark效应所产生的较高的载流子输入效率和复合发光效率。

High Internal Quantum Efficiency Blue Light-emitting Diodes with Triangular Shaped InGaN/GaN Multiple Quantum Wells

The internal quantum efficiency (IQE) of InGaN quantum wells (QWs) light-emitting diodes (LEDs) is numerically investigated, which involved its emission spectra, carrier concentrations, energy band, electrostatic field and internal quantum efficiency. Optical properties of InGaN/GaN LEDs with varied QW numbers are numerically studied. The results reveal that, for the LEDs with conventional rectangular shaped QWs, two quantum wells (2-QWs) units structure has better optical performance than 5-QWs and 7-QWs structures. The advantages of nitride-based LEDs with triangular shaped InGaN/GaN multiple quantum wells (MQWs) are also discussed. The simulation results indicate that the triangular shaped MQW LEDs exhibit a higher electrical luminescence (EL) intensity, higher IQE and a stronger light-output power than the conventional rectangular MQW LEDs. All the advantages are due to the higher carrier injection efficiency and recombination rate which are caused by the higher electron-hole wave function overlap, and small quantum confined stark effect (QCSE).