Growth and Electrical Properties of Zinc-Cadmium Sulfide Graded-Band-GAP Crystals.

摘要

Large quasi-single crystals of Zn(sub x)Cd(sub 1-x)S with increasing x along the growth direction, have been successfully grown by vapor-growth techniques. Typical dimensions are 15 X 3 X 4 mm. The growth mechanism is studied, and, as a result, it is believed that the thermal conductivity plays a decisive role. Position-dependent optical and electrical studies on these crystals have revealed that the crystals with a slowly varying composition can be described by a graded band gap while the properties of crystals having a more abrupt change in composition are determined by lattice defects. Most of the crystals exhibit photoluminescence and high-field electroluminescence at low temperatures. From the optical and electrical data an energy-band diagram for graded Zn(sub x)Cd(sub 1-x)S is deduced with the position-dependent band gap accounted for by the position-dependent electron affinity. (Author)