We extend a theory of well-width fluctuations for inhomogeneous exciton broadening in quantum wells by expressing the fluctuation of the width in terms of the statistical characteristics of the morphological roughnesses of each interface forming the well. This allows us to take into account a possibility of cross correlations between the interfaces. We show that these correlations strongly suppress a contribution of interface disorder to the inhomogeneous linewidths of excitons. We also demonstrate that the vertical cross correlations are crucial for explaining the variety of experimental data on the dependence of the linewidth upon thickness of the quantum well.

• Received 20 March 2004

DOI:https://doi.org/10.1103/PhysRevB.71.155303