Tuesday, September 10, 2013

Abstract-Photoexcited carrier recombination in wide m-plane InGaN/GaN quantum wells


S. Marcinkevičius1, K. M. Kelchner2, L. Y. Kuritzky2, S. Nakamura2, S. P. DenBaars2, and J. S. Speck2
1Department of Materials and Nanophysics, KTH Royal Institute of Technology, Electrum 229, 16440 Kista, Sweden
2Materials Department, University of California, Santa Barbara, California 93106, USA

Carrier recombination in single 10 nm wide m-plane homoepitaxial In0.15Ga0.85N/GaN quantum wells was examined by time-resolved photoluminescence. The radiative recombination time at 3.5 K was found to be short, about 0.5 ns. This value and the single-exponential luminescence decay show that the localized exciton recombination is not affected by the in-plane electric field. At room temperature, the nonradiative recombination was prevalent. The data indicate that the nonradiative recombination proceeds via efficient recombination centers. Complexes of Ga vacancies with oxygen and/or related interface defects are suggested to play this role and thus provide a direction for future improvements in materials' quality.
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