High efficiency and improved ESD characteristics of GaN-based LEDs with naturally textured surface grown by MOCVD

The following paper presents a study on GaN-based light-emitting diodes (LEDs) with naturally textured surface grown by metal-organic chemical vapor deposition. The study utilizes a well-known approach of increasing light extraction efficiency. The approach is based on naturally formed V-shaped pits on surface that originate from low-temperature-growth (LTG) conditions of topmost p-GaN contact layer. In our experiment, the high-temperature-grown (HTG) p-GaN layer was inserted between the p-AlGaN electron-blocking layer and the LTG p-GaN contact layer, in order to suppress pit-related threading dislocations (TDs). These TDs may intersect the underlying active layer. The results of the experiment show that GaN-based LEDs with the HTG p-GaN insertion layer can effectively endure negative electrostatic discharge voltage of up to 7000 V. We also noted that application of 20-mA current injection yields output power of about 16 mW for the LEDs emitting around 465 nm. The output power results correspond to an external quantum efficiency of around 30%.