Photoelectromagnetic effect in Hg1-xCdxTe epitaxial layers

A generalized model of the photoelectromagnetic effect (PME) in epitaxial layers (EL) is formulated that takes into account a presence of the space charge region (SCR) on the free surface and the graded gap region (GGR) at the interface with a substrate. It is shown that the diffusion currents of excess minority carriers, on the one hand, and their drift currents in SCR and GGR, on the other one, may flow in alternative directions and, when the latter currents dominate, the sign of photoelectromagnetic current JPME can take an opposite value thus allowing observation of the anomalous PME