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

Applying the self-consistent Greenʹs function method, we calculate and analyze the relaxation frequency ν of exciton in a quasi-two-dimensional quantum well of arbitrary depth. The exciton relaxation results from the electron and hole scattering by the randomly rough well interfaces. It is shown that the introduced here ν controls the behavior of the exciton absorptivity spectrum A(ω). We analyze the line-shape of the ground-state exciton resonance and reveal the criteria for the transition from asymmetric (sharp) to symmetric (broad) resonance. The dependencies of ν and A on the parameters of the exciton quantum well and its rough interfaces are found.