Thermal annealing effects on the physical properties of GaAsBi/GaAs/GaAs:Si structure

Abstract

GaAsBi is a new material called a highly mismatched alloy that has drawn attention regarding its special physical properties. The alloying of the GaAs matrix by Bi atom gives rise to a huge restructuring of the band structure. A rapid shrinkage in the bandgap energy and a splitting of the spin–orbit interaction band are noted. But the synthesis of this material requires unusual growth conditions in order to avoid the appearance of droplets on the surface and a native defects due to the non-stoichiometry. Consequently, an improvement of the physical properties is required to be used in device applications. In this perspective, we report an investigation of the effect of thermal annealing on the GaAsBi/GaAs/GaAs:Si structure. Photoreflectance, Spectroscopic ellipsometry are used to study the optical characteristics of this structure. High Resolution X-Ray Diffraction and Atomic Force Microscopy are employed as structural techniques for investigation.