EXAFS study of GaN/AlN multiple quantum wells grown by ammonia MBE

Zhuravlev, K. and Malin, T. and Trubina, S. and Erenburg, S. and Dobos, László and Pécz, Béla (2013) EXAFS study of GaN/AlN multiple quantum wells grown by ammonia MBE. PHYSICA STATUS SOLIDI C-CURRENT TOPICS IN SOLID STATE PHYSICS, 10 (3). pp. 311-314. ISSN 1862-6351

Text K.S.Zhuravlev EXAFS study of AlN-GaN SL pssc 10-311–2013.pdf Restricted to Repository staff only Download (1MB) | Request a copy

Abstract

Extended X-ray absorption fine structure above the Ga-K edge has been used to study the local structure of heterointerfaces in GaN/AlN multiple quantum wells (MQWs) grown by ammonia molecular beam epitaxy. The thickness of AlN and GaN layers in MQWs were evaluated using transmission electron microscopy, X-ray diffraction and Raman spectroscopy. Two sets of MQWs structures with the number of period about of 20 and more than 100 were studied. The Ga-Ga interatomic distance in MQWs is lower than that in bulk GaN due to elastic compression of GaN layers in MQWs. This effect is less pronounced in thick structures because of almost full relaxation of GaN layers. The Ga-Al interatomic distance in thick MQWs is too long, about 0.1 Å, longer than typical values for AlGaN alloys. Then number of Ga cations in the second coordination shell of Ga atoms is lower than that predicted for abrupt heterointerfaces that evidences intermixing of heterointerfaces. The intermixing degree depends on the total thickness of MQWs © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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