Effect of Stress on CdS Single Crystals

The electrical and luminescence properties of CdS crystals, which show the phenomenon of storage, have been studied as a function of hydrostatic pressure and uniaxial stress. In the excited state, uniaxial stress applied parallel to the c axis resulted in an irreversible increase of six orders of magnitude in the resistance. Uniaxial stress applied perpendicular to the c axis and hydrostatic pressure had no effect on the resistance. While uniaxial stress was being applied to the crystal in the low-resistivity state, luminescence was observed. The integrated intensity was independent of the rate of application of the stress over a range of ten to one, and the luminescence consisted of the characteristic green-edge emission and a red luminescence centering at about 6600 {}. At room temperature, the decay constant of the photocurrent increased with hydrostatic pressure.