Enhanced Light Extraction Efficiency and Modulation Bandwidth of Deep-Ultraviolet Light-Emitting Diodes with Al Nanospheres
Enhanced Light Extraction Efficiency and Modulation Bandwidth of Deep-Ultraviolet Light-Emitting Diodes with Al Nanospheres
复制标题
铝纳米球增强深紫外发光二极管的光提取效率和调制带宽
作者：
Xiao;Xu Liang;Lingyun Tang;Wen
采用三维时域有限差分方法对AlGaN基深紫外光发光二极管(DUV-LED)的平面、纳米和Al纳米球结构进行了数值模拟。从光提取效率(Lee)、普塞尔因数(FP)和调制带宽等方面对三种类型的DUV-LED进行了比较和分析。结果表明，具有最佳高度、宽度和间距的纳米柱结构DUV-LED可以将横向电场极化的LEE提高到39.7%，将横向磁极化的LEE提高到4.4%。这种显著的改善主要是由于增强了散射效应、降低了p-GaN层的吸收和全内反射(TIR)效应。采用Al纳米球后，当Al纳米球直径为120 nm时，TE极化的调制带宽增加了71 MHz，TM极化的LEE增加了约4.3倍。促进的原因主要归因于Al纳米球诱导的偶极和局域表面等离子体的耦合行为。所设计的结构为实现高效率的DUV-LED提供了有意义的解决方案。
Planar, nanopillar and Al nanosphere structure AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs) were numerically investigated via a three-dimensional finite difference time domain (3D FDTD) method. The three types of DUV-LEDs were compared and analyzed in terms of light extraction efficiency (LEE), Purcell factor (FP) and modulation bandwidth. The results showed that nanopillar structure DUV-LEDs with optimal nanopillar height, width and spacing can enhance transverse electric (TE)-polarized LEE to 39.7% and transverse magnetic (TM)-polarized LEE to 4.4%. The remarkable improvement was mainly due to the increased scattering effect, decreased absorption of the p-GaN layer and total internal reflection (TIR) effect. After adopting the Al nanospheres, the TE-polarized modulation bandwidth was increased by 71 MHz and the TM-polarized LEE was enhanced approximately 4.3-fold as compared to the nanopillar LED structure, while the Al nanosphere diameter was 120 nm. The reasons for promotion are mainly attributed to the coupling behavior of diploe and localized surface plasmon induced by Al nanospheres. The designed structures provide a meaningful solution for realization of high-efficiency DUV-LEDs.