12 March 2010 Internal quantum efficiency of m-plane InGaN on Si and GaN
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Proceedings Volume 7602, Gallium Nitride Materials and Devices V; 76021N (2010) https://doi.org/10.1117/12.843727
Event: SPIE OPTO, 2010, San Francisco, California, United States
High brightness InGaN light emitting diodes (LEDs) require high quantum efficiency and its retention at high injection levels. The efficiency drop at a high injection levels in InGaN light emitting diodes (LEDs) has been attributed, e.g. to polarization field on polar c-plane InGaN and the heavy effective hole mass which impedes high hole densities and transport in the active quantum wells. In this study, we carried out a comparative investigation of the internal quantum efficiency (IQE) of InGaN active region in LED structures using resonant optical excitation for layers with polar (0001) orientation on c-plane sapphire, and nonpolar (1-100) m-plane orientation, the latter on specially patterned Si and on m-plane bulk GaN. Analysis of the resonant photoluminescence (PL) intensity as a function of the excitation power indicate that at comparable generated carrier concentrations the IQE of the m-plane InGaN on Si is approximately a factor of 2 higher than that of the highly optimized c-plane layer. At the highest laser excitation level employed (corresponding carrier concentration n ~ 1.2 x 1018 cm-3), the m-plane LED structure on Si has an IQE value of approximately 65%. We believe that the m-plane would remain inherently advantageous, particularly at high electrical injection levels, even with respect to highly optimized c-plane varieties. The observations could be attributed to the lack of polarization induced field and the predicted increased optical matrix elements.
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J. Lee, J. Lee, X. Ni, X. Ni, M. Wu, M. Wu, X. Li, X. Li, R. Shimada, R. Shimada, Ü. Özgür, Ü. Özgür, A. A. Baski, A. A. Baski, H. Morkoç, H. Morkoç, T. Paskova, T. Paskova, G. Mulholland, G. Mulholland, K. R. Evans, K. R. Evans, } "Internal quantum efficiency of m-plane InGaN on Si and GaN", Proc. SPIE 7602, Gallium Nitride Materials and Devices V, 76021N (12 March 2010); doi: 10.1117/12.843727; https://doi.org/10.1117/12.843727

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