Photoelectrochemical roughening of p‐GaN for light extraction from GaN/InGaN light emitting diodes

Abstract

A method for photoelectrochemical (PEC) etching of Ga‐face, p ‐type GaN is presented using GaN/InGaN heterostructures. This technique, which does not require any special epitaxial structure, flip chip bonding, or complicated processing, is used to roughen p ‐side‐up lightemitting diodes (LEDs) to increase extraction efficiency. The extraction efficiency is increased by 20 ± 5% for roughened LEDs compared to nearby unetched LEDs, without any effect on the electrical properties of the devices. This is the first report of rapid, external‐bias free PEC etching of p ‐type GaN, which could have broad applications to low‐damage selective etching for a variety of electronic and optical devices. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

(Invited) Luminescence Properties of Silicon-Rich Silicon Nitride Films and Light Emitting Devices

“…, 35 (18) 3-19 (2011) nm to 500 nm. Besides, the surface of ITO electrode became much rougher by the introduction of Ag island film, which can reduce the inner-reflection of light and increase the light extraction efficiency of the devices (48). As shown in Fig.…”

Enhancement of light-extraction efficiency of SiNx light emitting devices through a rough Ag island film

“…V C 2012 American Institute of Physics 100, 031113-1 inner-reflection of light and significantly increase the light extraction efficiency of the device. 11,12 We estimated the contribution of this roughening on the enhancement of the light extraction efficiency of LEDs quantitatively based on the total integrated scatter (TIS), which was defined as the total power scattered into a hemisphere divided by the incident power. 4 Under the assumption that the scattering mainly occurs at the regular reflection direction, the TIS is given as…”

Emission enhancement from nonpolar a-plane III-nitride nanopillar

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“…The PL spectrum in Fig. 17 Examination of Fig. Despite the significant removal of active material, the overall emission efficiency increased due to the suppression of in-plane wave-guiding effects.…”