In situ asymmetric island sidewall growth of high-quality semipolar (112̄2) GaN on m-plane sapphire. Issue 29 (21st June 2016)

• Record Type: Journal Article
• Authors: Wu, Zhengyuan; Shen, Xiyang; Liu, Chuan; Li, Kongyi; Shen, Wenzhong; Kang, Junyong; Fang, Zhilai
• Is Part Of: CrystEngComm. Volume 18:Issue 29(2016)
• Page Start: 5440
• Page End: 5447
• Publication Date: 2016-06-21
• Subjects: Crystals -- Periodicals; Crystal growth -- Periodicals; Crystallography -- Periodicals; Cristaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Cristallographie -- Périodiques; 548
• DOI: 10.1039/c6ce00878j
• Languages: English
• ISSNs: 1466-8033

Abstract

Abstract : In situ asymmetric island sidewall growth (AISG) was developed to enhance Ga-face facet growth and improve the crystalline quality of (112̄2) GaN epilayers on m -plane sapphire substrates. Abstract : In situ asymmetric island sidewall growth (AISG) was developed to enhance Ga-face facet growth and improve the crystalline quality of (112̄2) GaN epilayers on m -plane sapphire substrates. In the early growth stage island shaping and sidewall faceting were distinct and controlled by growth design. Using in situ AISG, {0002} instead of {1̄103} sidewall facets were formed on the Ga-rich island surface, which eliminated formation of a {1̄103} phase during subsequent layer growth of semipolar GaN. Enhanced Ga-face sidewall facet growth led to + c regions overlapping − c regions, which reduced defect density. Pure semipolar (112̄2) epilayers with a reduced surface striation density and a basal-plane stacking fault density of 8 × 10 3 cm −1 were obtained. The observation of a narrow EH2 peak and an intense E1 (LO) peak in Raman spectra indicates that almost strain-free high-quality semipolar (112̄2) GaN films were achieved. The photoluminescence emission intensity from the (112̄2) GaN film prepared by in situ AISG was dominated by band-edge emission and enhanced ∼4 times more than that from conventional (112̄2) GaN.