GaN/AlGaN multiple quantum wells grown on transparent and conductive (-201)-oriented β-Ga2O3 substrate for UV vertical light emitting devices

Ajia, I. A. and Yamashita, Y. and Lorenz, K. and Muhammed, M. M. and Spasevski, L. and Almalawi, D. and Xu, J. and Iizuka, K. and Morishima, Y. and Anjum, D. H. and Wei, N. and Martin, R. W. and Kuramata, A. and Roqan, I. S. (2018) GaN/AlGaN multiple quantum wells grown on transparent and conductive (-201)-oriented β-Ga2O3 substrate for UV vertical light emitting devices. Applied Physics Letters, 113 (8). 082102. ISSN 0003-6951 (https://doi.org/10.1063/1.5025178)

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Abstract

GaN/AlGaN multiple quantum wells (MQWs) are grown on a 2 ¯ 01-oriented β-Ga2O3 substrate. The optical and structural characteristics of the MQW structure are compared with those of a similar structure grown on sapphire. Scanning transmission electron microscopy and atomic force microscopy images show that the MQW structure exhibits higher crystalline quality of well-defined quantum wells when compared to a similar structure grown on sapphire. X-ray diffraction rocking curve and photoluminescence excitation analyses confirm the lower density of dislocation defects in the sample grown on a β-Ga2O3 substrate. A detailed analysis of time-integrated and time-resolved photoluminescence measurements shows that the MQWs grown on a β-Ga2O3 substrate are of higher optical quality. Our work indicates that the 2 ¯ 01-oriented β-Ga2O3 substrate can be a potential candidate for UV vertical emitting devices.

ORCID iDs

Ajia, I. A., Yamashita, Y., Lorenz, K., Muhammed, M. M., Spasevski, L. ORCID logoORCID: https://orcid.org/0000-0002-7409-3807, Almalawi, D., Xu, J., Iizuka, K., Morishima, Y., Anjum, D. H., Wei, N., Martin, R. W. ORCID logoORCID: https://orcid.org/0000-0002-6119-764X, Kuramata, A. and Roqan, I. S.;