Improved crystal quality of nonpolar a-plane GaN based on the nano pattern formed by the annealed thin Ni layer

Abstract

Abstract A method to improve the nonpolar (11–20) a-plane GaN crystalline quality is investigated. The promoted crystal quality of a-plane GaN is achieved through growing on the a-plane GaN template with nano pattern. For on-axis (11–20) plane X-ray rocking curves, the full width at half maximum values are remarkably reduced from 2834 to 1210 arcsec, 2868 to 780 arcsec along the m-axis and the c-axis directions, respectively. Also, the improved crystalline quality results in the better optical properties according to the photoluminescence and Raman measurements. Moreover, the cross-sectional transmission electron microscopy is also used to study the mechanisms of dislocation reduction. Evidently, this technique is effective in promoting crystal quality of nonpolar a-plane GaN.