Surface morphology and optical properties of InGaN/GaN multiple quantum wells grown on freestanding GaN (0001) substrates. (December 2016)

• Record Type: Journal Article
• Authors: Zhou, Kun; Ren, Huaijin; Liu, Jianping; Ikeda, Masao; Ma, Yi; Gao, Songxin; Tang, Chun; Yang, Hui
• Is Part Of: Superlattices and microstructures. Volume 100(2016)
• Page Start: 968
• Page End: 972
• Publication Date: 2016-12
• Subjects: Surface morphology -- Metalorganic vapor phase epitaxy -- Free-standing GaN -- InGaN multiple quantum well -- Off-cut; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2016.10.067
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: Surface morphology and optical properties of InGaN-based multiple quantum wells grown on c-plane freestanding GaN substrates by metalorganic vapor phase epitaxy was investigated. The surface shows a dependence on the substrate crystallographic orientation, presenting wavy and mirror-like feature with the substrate off-cut towards the [ 11 2 ¯ 0 ] direction and the [ 1 1 ¯ 00 ] direction, respectively. To get sharp hetero-interfaces, InGaN multiple-quantum-wells-based blue laser diode wafers were grown on substrates with off-cut towards the [ 1 1 ¯ 00 ] direction. The photoluminescence peak wavelength of the blue laser wafers shows a linearly blue shift as the substrate off-cut angle increases. A minimum spectra line width of 90 meV@450 nm can be obtained with a substrate off-cut angle of about 0.5°. These surface and optical properties were ascribed to the step growth kinetics of the wurtzite type materials. Highlights: The surface morphology of homoepitaxial GaN (0001) was studied. The surface morphology shows a dependence on the substrate crystallographic orientation. InGaN-based blue laser diode wafers were grown on substrates with off-cut towards the [ 1 1 ¯ 00 ] direction. The photoluminescence peak wavelength and spectra line width of laser diode show substrate off-cut angle dependence. An off-cut angle of around 0.5° towards the [ 1 1 ¯ 00 ] direction is a more optimized substrate parameter.