Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524


Condensed Matter

J. Korean Phy. Soc. 2006; 49(5): 2001

Published online November 15, 2006

Copyright © The Korean Physical Society.

Comparison of InxGa1-xN/GaN MQWs Grown on GaN and Sapphire Substrates

T. S. Kim, J. Y. Park, T. V. Cuong and C.-H. Hong


In$_x$Ga$_{1-x}$N/GaN multi quantum wells were grown on GaN and sapphire substrates by using metal-organic chemical-vapor deposition. A detailed analysis of the satellite peaks observed in the high-resolution X-ray diffraction patterns showed the presence of more compressive strain in In$_x$Ga$_{1-x}$N/GaN MQWs grown on GaN substrates than in the MQWs grown on sapphire substrates. However, the optical investigations of the In$_x$Ga$_{1-x}$N/GaN MQWs grown on GaN, showed a lower Stokes-like shift in photoluminescence than the same MQWs grown on sapphire did. The Stokes-like shift observed for MQWs is attributed to a potential fluctuation and the quantum confined Stark effect induced by the built-in internal field due to spontaneous and strain-induced piezoelectric polarizations.