Growth and characterization of mixed polar GaN columns and core-shell LEDs

• Published in: Physica status solidi. A, Applications and materials science Vol. 212; no. 4; pp. 727 - 731
• Main Authors: Wang, Xue, Jahn, Uwe, Mandl, Martin, Schimpke, Tilman, Hartmann, Jana, Ledig, Johannes, Straßburg, Martin, Wehmann, Hergo-H., Waag, Andreas
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 01.04.2015; Wiley Subscription Services, Inc
• Subjects: core-shell LED; Damkohler number; Epitaxy; Gallium nitrides; GaN; Materials science; mixed polarity; Optical properties; Silicon dioxide; Strain; Vapor phase epitaxy
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.201400362

The growth mechanisms of selective area growth of GaN microcolumns by metal organic vapor phase epitaxy on patterned SiOx/sapphire templates, are investigated. Both Ga‐ and N‐polar domains within a GaN column are detected. The growth system of mixed polar GaN columns is near reaction limitation, which is quantitatively determined by the Damköhler number. The major part of the mixed polar GaN columns is N‐polar. However, the Ga‐polar domains increase the vertical growth rate of the whole column. The strain status of the columns is almost totally relaxed. Core–shell LED structures were realized on the mixed polar GaN columns. The optical properties of the core–shell LEDs were characterized.