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Hexagonal Pyramids Shaped GaN Light Emitting Diodes Array by N-polar Wet Etching

  • Jun Ma (a1), Liancheng Wang (a1), Zhiqiang Liu (a1), Guodong Yuan (a1), Xiaoli Ji (a1), Ping Ma (a1), Junxi Wang (a1), Xiaoyan Yi (a1), Guohong Wang (a1) and Jinmin Li (a1)...


In this work, we investigated the influence of N-polar wet etching on the properties of nitride-based hexagonal pyramids array (HPA) vertical-injection light emitting diodes (V-LEDs). The cathodeluminescence images showed the randomly distribution of hexagonal pyramids with isolated active regions. The transmission electron microscopy images demonstrated the reduced density of threading dislocations. The IQE was estimated by temperature dependence of photoluminescence, which showed 30% increase for HPA V-LEDs compared with broad area (BA) V-LEDs. The improved extraction efficiency was verified by finite difference time domain simulation, which was 20% higher than that of roughened BA V-LEDs. The electrical properties of HPA V-LEDs were measured by conductive atomic force microscopy (CAFM) measurements. HPA V-LEDs exhibited much lower leakage current due to the improved crystal quality.


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