Cadmium telluride (CdTe) is an interesting semiconductor compound whose photoelectronic properties make it suitable for solar cell applications. We report here a study of defects in CdTe, carried out by lattice resolution imaging in a transmission electron microscope (TEM), during which observations were made of the motion of image spots at the edge of a specimen. As the spots are related to the projected atomic positions in the structure, this behaviour indicates atomic motion at the CdTe surface. Individual spot jumps occurred several times per second and one could watch the formation and decay of small crystalline facets. The possibility thus arises for surface studies, at the atomic level, in conjunction with direct crystal lattice imaging, allowing investigation of the interaction between surface atoms and their substrate. © 1981 Nature Publishing Group.