Close-spaced sublimation growth of homo- and hetero-epitaxial CdTe thick films

This paper reports on the growth using a modified close space sublimation of good epitaxial CdTe layers on GaAs substrates and a multi-grain CdTe seedplate. Decreasing the substrate–source distance to a few millimetres improves the substrate–vapour interfacial stability and homogeneity and slows the growth rate and thus the nucleation process. The defects and grain boundaries of a multi-grain seed were reproduced in the film. “Dual-epitaxial” was observed on both (1 0 0) and mis-oriented (1 0 0) GaAs substrates. Growth rates of 5–20 μm/h and FWHM values as low as 300 arcsec were recorded from ∼120 μm thick CdTe(2 1 1) B films, the surface morphology of which differed from those grown by other PVT methods.