title: InGaN light emitting diodes with a laser-treated tapered GaN structure.
abstract: InGaN light-emitting diode (LED) structures get an air-void structure and a tapered GaN structure at the GaN/sapphire interface through a laser decomposition process and a lateral wet etching process. The light output power of the treated LED structure had a 70% enhancement compared to a conventional LED structure at 20 mA. The intensities and peak wavelengths of the micro-photoluminescence spectra were varied periodically by aligning to the air-void (461.8nm) and the tapered GaN (459.5nm) structures. The slightly peak wavelength blueshift phenomenon of the EL and the PL spectra were caused by a partial compressed strain release at the GaN/sapphire interface when forming the tapered GaN structure. The relative internal quantum efficiency of the treated LED structure (70.3%) was slightly increased compared with a conventional LED (67.8%) caused by the reduction of the piezoelectric field in the InGaN active layer.
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Wan-Chun
authors.initials: WC
authors.lastname: Huang
authors.forename: Chia-Feng
authors.initials: CF
authors.lastname: Lin
authors.forename: Tsung-Han
authors.initials: TH
authors.lastname: Hsieh
authors.forename: Sin-Han
authors.initials: SH
authors.lastname: Chen
authors.forename: Ming-Shiou
authors.initials: MS
authors.lastname: Lin
authors.forename: Kuei-Ting
authors.initials: KT
authors.lastname: Chen
authors.forename: Chun-Min
authors.initials: CM
authors.lastname: Lin
authors.forename: Sy-Hann
authors.initials: SH
authors.lastname: Chen
authors.forename: Pin
authors.initials: P
authors.lastname: Han