Transmission electron microscopy was used to investigate CdTe(111) which had been grown onto GaAs(100) by using molecular beam epitaxy. A loop structure which had previously been observed by using photoluminescence microscopy was identified as being the boundary between twinned microcrystallites that extended from the CdTe/GaAs interface to the CdTe surface. When viewed along the growth axis, the boundaries between these columnar twins appeared as loops and segments. The surface roughness of the GaAs substrate contributed to the initial growth of twinned material. This then led to competitive growth between the twins, and to the creation of the observed columnar twins.

J.L.Reno, M.J.Carr, P.L.Gourley: Journal of Applied Physics, 1990, 67[9], 4114-7