Photocarrier transport and recombination in an asymmetric quantum well subjected to a focused excitation

Electron and hole transport in an InGaAs/InP asymmetric quantum well are investigated by surface scanning the microluminescence signal from the quantum well recombination. Under illumination by a tightly focused laser beam, we show that a novel in-plane hole diffusion process occurs in the quantum well, to which we associate an effective hole lifetime. This effective lifetime is dependent upon the electron accumulation, a result expected to allow an alternative estimate of the two-dimensional (2D) electron density. Vertical and in-plane transport and recombination processes are additionally investigated in connection with observed temperature-dependent saturation of the luminescence intensity.