International Commission for Optics Topical Meeting, Delhi, Kanada, 7 - 09 Ekim 2009, cilt.1288, ss.178-180
We report the optoelectronic properties of In-rich In1-xGaxN samples grown on sapphire substrates by MBE. Optical properties were determined by photoluminescence spectroscopy at temperatures between T=10 K and 300 K. The results indicate that the PL peak energy has very weak temperature dependence and the optical absorption edge energy increases with increasing Ga content as previously reported in the literature. In this paper we suggest that this observation might be explained in terms of strong carrier localization due to a large compositional inhomogeneity. Hall measurements were also performed at temperatures between T=77 K and 300 K. All intentionally undoped samples were n-type and increasing Ga content reduced the electron mobility associated with reduced crystalline quality. The weak temperature dependence of the electron mobility is explained in terms of enhanced screening effect between electrons and optical phonons.