Energy gap: 2.4ev.
The colour of pure cadmium sulphide is pale yellow. It melts only under at high temperature. It can be prepared in the resistivity range from 10 to about 1012Ω-cm depending on the presence of defects and the impurities. it can be prepared as an semiconductor device and is extremely difficult to produce P-type cadmium sulphide. It has been used commercially as a photo conductor for many years as well as constituent of cathode ray phosphorous.