Influence of polarization charges on the current in CdS single crystals

Results are reported for a study of dark currents in samples of CdS single crystals which was conducted to clarify the relaxation mechanism of dark currents in such crystals and the role of polarization charges in this process. Relaxation curves for a dark current in a crystal sample are presented which indicate a high degree of polarization. It is shown that significant polarization fields are produced in CdS-type semiconductors, that these fields result from phenomena in the contact regions, and that this effect is not associated with charge-transfer centers in the crystal solid. The static dielectric constant of a CdS single crystal is calculated and shown to be dependent on the intensity of the polarizing field.