Formation of CuPt-type ordered (Cd, Zn)Te at CdTe/ZnTe interface

A CuPt-type ordered CdZnTe has been observed at CdTe/ZnTe interface sequentially grown by organometallic vapor-phase epitaxy on (0 0 1)GaAs at 400°C. Selected area electron diffraction, cross-sectional high-resolution electron microscopy, and computer image simulation have been employed to characterize the ordered structure in CdZnTe. Between CdTe and ZnTe, we observed a relatively uniform layer with dark contrast band image by conventional transmission electron microscopy. Through [1 1 0] projection, selected area electron diffraction pattern showed two sets of {1/2 1/2 1/2} extra spots with symmetrical intensity and corresponding high-resolution images showed doubling periodicity in contrast on {1 1 1} lattice planes. The ordered structure has been identified as CuPt-type ordered CdZnTe from electron diffraction, high-resolution images, and computer image calculations. Through [1 1 0] projection, it was observed that there were two variants for ordering according to each direction of doubling periodicity on {1 1 1} lattice planes, i.e., on (1 1 1) and on (1 1 1). Each variant was observed to have its own domain structure of which size ranged from 10 to 20 nm and the two variants were observed with equal probability.