title: InGaN Light-Emitting Diodes with an Embedded Nanoporous GaN Distributed Bragg Reflectors.
abstract: InGaN light emitting diodes (LED) structure with an embedded 1/4λ-stack nanoporous-GaN/undoped-GaN distributed Bragg reflectors (DBR) structure have been demonstrated. Si-heavily doped GaN epitaxial layers (n(+)-GaN) in the 12-period n(+)-GaN/u-GaN stack structure are transformed into low refractive index nanoporous GaN structure through the doping-selective electrochemical wet etching process. The central wavelength of the nanoporous DBR structure was located at 442.3 nm with a 57 nm linewidth and a 97.1% peak reflectivity. The effective cavity length (6.0λ), the effective penetration depth (278 nm) in the nanoporous DBR structure, and InGaN active layer matching to Fabry-Pérot mode order 12 were observed in the far-field photoluminescence radiative spectra. High electroluminescence emission intensity and line-width narrowing effect were measured in the DBR-LED compared with the non-treated LED structure. Non-linear emission intensity and line-width reducing effect, from 11.8 nm to 0.73 nm, were observed by increasing the laser excited power. Resonant cavity effect was observed in the InGaN LED with bottom nanoporous-DBR and top GaN/air interface.
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, Taichung, 402, Taiwan.
authors.forename: Guo-Yi
authors.initials: GY
authors.lastname: Shiu
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, Taichung, 402, Taiwan.
authors.forename: Kuei-Ting
authors.initials: KT
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, Taichung, 402, Taiwan.
authors.forename: Feng-Hsu
authors.initials: FH
authors.lastname: Fan
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, Taichung, 402, Taiwan.
authors.forename: Kun-Pin
authors.initials: KP
authors.lastname: Huang
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, Taichung, 402, Taiwan.
authors.forename: Wei-Ju
authors.initials: WJ
authors.lastname: Hsu
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, Taichung, 402, Taiwan.
authors.forename: Jing-Jie
authors.initials: JJ
authors.lastname: Dai
authors.affiliation: Department of Photonics, Feng Chia University, 100, Wenhwa Road, Seatwen, Taichung 40724, Taiwan.
authors.forename: Chun-Feng
authors.initials: CF
authors.lastname: Lai
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, Taichung, 402, Taiwan.
authors.forename: Chia-Feng
authors.initials: CF
authors.lastname: Lin