TEMPERATURE EFFECTS IN THE PHOTOCONDUCTIVITY OF HIGH-RESISTANCE Cu2O

Abstract

Measurements were made at a number of different wavelengths to find the temperature dependence of the photoconductivity in Cu2O of resistivity greater than 108 ohm-cm between +100 °C and −100 °C. A number of features of this temperature dependence are discussed with particular reference to making a-c. measurements on a slowly responding photoconductor. It is shown that as the chopping period becomes short in comparison with the response time of the photoconductor, the r.m.s. photoconductivity will decrease linearly with the chopping period for three different types of response considered. Photoresponse at room temperature was also measured on Cu2O after two methods of vacuum annealing, one at 1 000 °C and the other at 300 °C. The former shows a sensitivity only for wavelengths less than 0.6 μ, whereas the latter shows the more usual behavior of a peak near 0.6 μ, with sensitivity measurable well into the near infrared.