Low-temperature anomalies of the photoelectromagnetic effect in p-Cd x Hg1 − x Te due to recharging of surface states

A number of anomalies inexplicable in the context of available theoretical models are observed in the photoelectromagnetic effect in p-Cd _x Hg_{1 ? x} Te crystals. A general model of the photoelectromagnetic effect in semiconductors with a large ratio between the mobilities of electrons and holes is developed, taking into account the influence of space charge. The model allows the interpretation of all experimentally observed anomalies of the photoelectromagnetic effect, including the double sign inversion in magnetic field. Comparison of the theory with the experiment makes it possible to determine the parameters of the material. It is suggested that the space charge responsible for the anomalies of the photoelectromagnetic effect is associated with a high concentration of specific surface states (～10¹³ cm^?3) recharged when trapping nonequilibrium charge carriers.