GaN-Based Light Emitting Diodes with Hybrid Micro-Nano Patterned Sapphire Substrate

GaN-based light emitting diodes (LEDs) have been fabricated with hybrid micro-nano patterned sapphire substrate (MNPSS). Random nano pattern distributed on the spacing and inclined surface of the micro pattern was realized utilizing standard photolithography, nickel etching mask and inductively coupled plasma (ICP) etching techniques. Both surface morphology and X-ray diffraction (XRD) results showed that MNPSS and conventional MPSS had similar effect on the crystalline quality of the epilayers. Furthermore, light output powers (LOP) of LEDs with MNPSS was increased considerably compared with conventional planar sapphire substrate (CPSS) and was even higher than that of LEDs employing micro patterned sapphire substrate (MPSS), indicating more superior performance of GaN-based LEDs was obtained by employing the hybrid micro-nano pattern. (C) 2013 The Electrochemical Society. All rights reserved.