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Title: Partial strain relaxation effects on polarization anisotropy of semipolar (112{sup ¯}2) InGaN/GaN quantum well structures

Partial strain relaxation effects on polarization anisotropy of semipolar (112{sup ¯}2) InGaN/GaN quantum well (QW) structures were investigated using the multiband effective-mass theory. In the case of strain relaxation of ϵ{sub x′x′} along x′-axis, the polarization ratio gradually decreases with increasing strain relaxation. Also, with the strain relaxation by the same amount, the variation of the polarization ratio along x′-axis is shown to be much larger than that along y′-axis. However, the polarization switching is not observed even at a high In composition of 0.4 due to a small strain component (ϵ{sub x′x′}{sup 0}) with no strain relaxation. On the other hand, in the case of strain relaxation of ϵ{sub y′y′} along y′-axis, the polarization switching is observed, and the optical anisotropy is found to change from positive to negative with increasing strain relaxation. Also, the absolute value of the polarization ratio gradually decreases with increasing carrier density. However, the polarization switching due to the carrier density is not observed. Thus, the polarization switching observed at high carrier density may be attributed to inhomogeneous strain distribution in the InGaN layer.
Authors:
 [1] ; ;  [2] ; ;  [3] ; ; ; ;  [4]
  1. Department of Electronics Engineering, Catholic University of Daegu, Hayang, Kyeongbuk 712-702 (Korea, Republic of)
  2. Advanced Institutes of Convergence Technology, Seoul National University, Suwon (Korea, Republic of)
  3. Department of Mechanical Engineering, Ajou University, Suwon (Korea, Republic of)
  4. Computational Science Group, CAS Center, SAIT, Samsung Electronics, Yongin-si, Kyunggi-do 446-712 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22253940
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 103; Journal Issue: 22; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANISOTROPY; CARRIER DENSITY; GALLIUM NITRIDES; POLARIZATION; QUANTUM WELLS; RELAXATION; STRAINS