Phase method for the determination of the lifetime of nonequilibrium carriers in photoconductors

A method for measuring the nonequilibrium carrier lifetime τ (of the order of 10^–9–10^–11 sec) was developed and tested on photoconductors: it is based on measurement of the phase shift of the photoresponse by an optical delay line. Measurements were made of the lifetime in Ge:Zn^II samples and the values of τ were found to be in the range 7×10^–11–7×10^–10 sec. The results obtained were compared with the lifetimes deduced from the amplitude-frequency characteristics of the photoresponse and with the results of a numerical calculation. The errors of the new method were analyzed.