Title of Paper:Crack-free ultraviolet AlGaN/GaN distributed Bragg reflectors grown by MOVPE on 6H-SiC(0001)

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Date of Publication:2014-06-01

Journal:SUPERLATTICES AND MICROSTRUCTURES

Included Journals:SCIE、EI

Volume:70

Page Number:54-60

ISSN No.:0749-6036

Key Words:Distributed Bragg reflectors; Metal organic vapor phase epitaxy; Double AlN/AlGaN layer buffer; Ultraviolet

Abstract:Ultraviolet AlGaN/GaN distributed Bragg reflectors (DBRs) were grown on 2 in. Si-face 6H-SiC(0001) by metal organic vapor phase epitaxy (MOVPE). Two samples with single AlGaN buffer layer and AlN/AlGaN double buffer layers were introduced to grow AlGaN/GaN DBRs. The optical microscope images show that there are plenty of cracks on the surface of the DBR with single AlGaN buffer. While for DBR with AlN/AlGaN double buffer layer are free of cracks. A 30 period of Al0.2Ga0.8N/GaN DBR was obtained with measured reflectance of over 92%. The crack-free DBR has a stop-band centered around 395 nm with a FWHM at 14 nm. ( C) 2014 Elsevier Ltd. All rights reserved.