Roughness of CdTe thin films grown on glass by hot wall epitaxy

Abstract

Cadmium telluride films were grown on glass substrates using the hot wall epitaxy(HWE) technique. The samples were polycrystalline with a preferential (111)orientation. Scanning electron micrographs reveal a grain size between 0.1 and0.5 µm. The surface morphology of the samples was studied by measuring the roughnessprofile using a stylus profiler. The roughness as a function of growth time andscale size were investigated to determine the growth and roughness exponents,β and α, respectively. From the results we can conclude that the growthsurface has a self-affine character with a roughness exponentα equalto 0.69 ± 0.03 and almost independent of growth time. The growth exponentβ wasequal to 0.38 ± 0.06. These values agree with that determined previously for CdTe(111) films grown onGaAs(100).