Influence of Well-Width Fluctuations on the Electronic Structure of GaN/AlxGa1-xN Multiquantum Wells with Graded Interfaces

E. Valcheva a, S. Dimitrov a, B. Monemar b, H. Haratizadeh b, P.O.A. Persson b, H. Amano c and I. Akasaki c a Faculty of Physics, Sofia University, 5 J. Bourchier Blvd, 1164 Sofia, Bulgaria b Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping, Sweden c Department of Electrical and Electronic Engineering, Meijo University, 1-501 Shiogamaguchi, Temkuku, Nagoya 468, Japan

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Received: 9 06 2007;

Experimental and computation results based on chemical composition assessment of metal-organic chemical vapour deposition grown undoped GaN/AlxGa1-xN multiquantum well structures in the low composition limit of x = 0.07 and wide wells demonstrate composition fluctuations in the barrier layers which lead to large-scale nonuniformities and inequivalence of the different wells. As a consequence the experimental photoluminescence spectra at low temperature show a double peak structure indicative of well-width fluctuations by one lattice parameter (2 monolayers).

DOI: 10.12693/APhysPolA.112.395 PACS numbers: 78.55.Cr, 73.20.-r, 73.21.-b, 74.40.+k