Study of GaAsBi / GaAs (11l) By Modulation Spectroscopy of Reflectance

Abstract

The Modulation Spectroscopy of Reflectance has been used to study the physical properties of GaAsBi alloys epitaxied on high Miller indices GaAs(11l)A substrate. The first part of this work constitutes an initiation step to, perfectly, manipulate this technique. Indeed, GaAs as bulk and thin film samples have been used to test and calibrate our setup. For this, several theoretical models have been successfully used to extract physical parameters such as: bandgap energy, spin orbit coupling, internal electric field and broadening parameter. The second part concerns the effect of GaAs substrate orientation (0 01, 111, 114, and 115) on the Bi content of GaAsBi alloy. A systematic study of series of GaAsBi/GaAs/GaAs(hkl) samples elaborated in same growth chamber proves that photoreflectance is a powerful tool for characterizing optical properties of new materials.