Effect of inter-wall surface roughness correlations on optical spectra   of quantum well excitons
  We show that the correlation between morphological fluctuations of two interfaces confining a quantum well strongly suppresses a contribution of interface disorder to inhomogeneous line width of excitons. We also demonstrate that only taking into account these correlations one can explain all the variety of experimental data on the dependence of the line width upon thickness of the quantum well. 
I.V. Ponomarev, L.I. Deych, A. A. Lisyansky