A semiempirical line shape model of GaAs MQW structures

We have developed a semiempirical model to describe the line shape in the vicinity of the exciton absorption lines in GaAs multiple quantum well (MQW) structures. This model is based on a conventional line-broadening analysis similar in spirit to that used in atomic and plasma physics. The absorption spectrum is determined through the line positions, oscillator strengths, homogeneous and inhomogeneous broadening, and continuum shifts. Values for these parameters are derived from a combination of theoretical models, some existing in the literature and other developed by the authors, and experimental data where theory is lacking. Our results are in good agreement with the absorption measurements and the nonlinear coefficients available in the literature. This model shows improvements in the nonlinearity at low temperature and small inhomogeneous linewidth, which is as expected