SOME EFFECTS IN A2B6 CRYSTALS IN HIGH ELECTRIC FIELDS RELATED TO TEMPERATURE QUENCHING OF PHOTOCONDUCTIVITY

Highly inhomogeneous distributions of the electric field strength, of the current, and of the temperature may arise in photoconductive AIIBVI crystals in strong electric fields. The distributions may be parallel to the current and transversal to it. The phenomenon is due to a combination of two processes – the temperature quenching of photoconductivity and the Joule heating. In the case of the transversal inhomogeneity the current lines are forced towards the surface of the sample. In the case of the longitudinal inhomogeneity the region of high electric field and elevated temperature occurs inside the sample. Under certain conditions this region becomes unstable and spontaneous infralow current oscillations arise. The importance of these phenomena is pointed out for the ultrasonic amplification by drifting electrons in photoconductive materials. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim