Large-area epitaxial CdTe(100) films grown on GaAs(100) substrates: MBE growth and substrate temperature effect

Abstract

The epitaxial growth of high-quality thin films provides a powerful method for the rapid preparation of new materials and discovery of materials with promising properties. Here, we report the effect of substrate temperature on the epitaxial growth of high-quality and large-area epitaxial CdTe films on GaAs(100) by molecular beam epitaxy. RHEED patterns as a function of the substrate temperature showed sharp streaky lines. A CdTe epilayer grown at 320 °C showed the narrowest full-width at half-maximum (FWHM) of 180 arcsec from (004) reflection in X-ray rocking curve measurements. The smooth and flat surface observed in the AFM image showed the excellent uniformity of the thin film, and the surface roughness decreased monotonically with the substrate temperature. From the substrate temperature dependence of the (A0, X) emission line, the luminescence intensity was found to increase with increasing substrate temperature, while the FWHM decreased with substrate temperature. Our experimental data suggest that the substrate temperature plays an important role in establishing hetero-epitaxial film growth for semiconductor devices.