Nonlinear theory of the photomagnetoelectric effect with a quadratic relationship between carrier densities: Light intensity dependence

A theory of the photomagnetoelectric (PME) effect in the presence of a recombination mechanism, which involves a quadratic relationship between the carrier densities, is developed. Analytical expressions of PME short-circuit current (IPME) and photoconductance (ΔG) are found by solving the nonlinear continuity equation, in the case in which the light is strongly absorbed on the front surface of the sample. The power law of IPME versus the light intensity is quadratic for high values of surface-recombination velocity and becomes linear for low values of this parameter. Similarly, the photoconductance has a linear dependence on light intensity for high surface-recombination velocities and a sublinear one for lower values of this last quantity. In all cases the IPME-vs-ΔG behavior shows a quadratic power law. Finally, the dependence of IPME and ΔG on the parameters of the recombination model is discussed.