Titanium induced polarity inversion in ordered (In, Ga)N/GaN nanocolumns. (13th January 2016)

• Record Type: Journal Article
• Authors: Kong, X; Li, H; Albert, S; Bengoechea-Encabo, A; Sanchez-Garcia, M A; Calleja, E; Draxl, C; Trampert, A
• Is Part Of: Nanotechnology. Volume 27:Number 6(2016)
• Publication Date: 2016-01-13
• Subjects: GaN nanocolumn -- transmission electron microscopy -- electron energy-loss spectroscopy -- inversion domain -- selective area growth -- nanowire; 81.15.Hi -- 68.35.B- -- 68.55.A- -- 61.05.jh; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/0957-4484/27/6/065705
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: We report on the formation of polarity inversion in ordered (In, Ga)N/GaN nanocolumns grown on a Ti-masked GaN-buffered sapphire substrate by plasma assisted molecular beam epitaxy. High-resolution transmission electron microscopy and electron energy-loss spectroscopy reveal a stacking fault-like planar defect at the homoepitaxial GaN interface due to Ti incorporation, triggering the generation of N-polar domains in Ga-polar nanocolumns. Density functional theory calculations are applied to clarify the atomic configurations of a Ti monolayer occupation on the GaN (0002) plane and to prove the inversion effect. The polarity inversion leads to an enhanced indium incorporation in the subsequent (In, Ga)N segment of the nanocolumn. This study provides a deeper understanding of the effects of Ti mask in the well-controlled selective area growth of (In, Ga)N/GaN nanocolumns.