Molecular-beam epitaxy and optical characterization of GaAs on CaF2 substrates

Abstract
The growth of GaAs layers on bulk fluoride substrates is reported. The characteristics of the GaAs layers are studied by Raman and photoluminescence spectroscopies. The experimental results presented compare these GaAs layers to those grown on (Ca,Sr)F2/GaAs. It is shown that the crystalline quality of GaAs improves with the distance to the fluoride interface and that the layers are under compressive stress; in addition, it was found that the latter does not affect the photoluminescence efficiency.