Real-time viewing of dynamic processes on CdTe surfaces at elevated temperature

Online video recording with a high-resolution electron microscope has been used to study real-time atomic events occurring at cadmium telluride surfaces over a range of temperatures from 27°C to 500°C. Using the profile imaging mode of observation, different types of surface activity have been documented on (001), (111) and (110) surfaces. For example, the (001) surfaces displayed reversible phase transformations between 2×1 and 3×1 reconstruction at a transition temperature of about 200°C. The (111) surfaces exhibited sublimation by a ledge mechanism that depended upon the terminating surface: layer-by-layer removal invariably occurred for (110) surface terminations whereas bilayer removal was usually seen for terminations by (100) surfaces. Finally, the (110) surface rearranged by a hopping mechanism, but no substantial loss of material was observed.