Surface scattering frequency and optical absorptivity of exciton in quasi-two-dimensional quantum wells

Applying the self-consistent Green's function method, we calculate and anal yze the relaxation frequency nu of exciton in a quasi-two-dimensional quant um well of arbitrary depth. The exciton relaxation results from the electro n and hole scattering by the randomly rough well interfaces. It is shown th at the introduced here nu controls the behavior of the exciton absorptivity spectrum A(omega). We analyze the line-shape of the ground-state exciton r esonance and reveal the criteria for the transition from asymmetric (sharp) to symmetric (broad) resonance. The dependencies of nu and A on the parame ters of the exciton quantum well and its rough interfaces are found. (C) 20 01 Elsevier Science Ltd. All rights reserved.