Ambipolar lateral diffusion of photo-induced carriers in a moderate magnetic field

Abstract

The ambipolar lateral diffusion of photo-induced charge carriers restricted in a plane of a quantum well (QW) under a moderate (non-quantizing) magnetic field is studied theoretically in the framework of the drift-diffusion model. The continuity equation for this case is solved exactly. The analytical expressions for the concentration of photo-induced electrons and the built-in electric field in the practically important cases of uniform and bell-shaped light beams are obtained in a closed form. It is shown that the ambipolar lateral diffusion of photo-induced charge carriers can be suppressed in InGaAs/GaAs QWs by a moderate magnetic field of ∼0.5 mT.