Low-temperature anomalies exhibited by the photoelectromagnetic effect in p-type CdxHg1−x Te

Abstract

When p-type crystals of CdxHg1−xTe (x=0.20–0.30) are placed in a magnetic field in the temperature range where holes freeze out onto acceptor states (T<30 K), the current associated with the photoelectromagnetic effect (PEME) is found to exhibit sign changes. It is shown that the reason for this anomalous behavior of the PEME is the changing ratio of concentrations of equilibrium and nonequilibrium current carriers. The theoretical model derived here, which takes into account the dependence of the effective ambipolar diffusion length on this concentration ratio, gives a good description of the PEME anomalies observed in experiment.