GROWTH INTERRUPTION INDUCED INTERFACE MICROROUGHNESS IN SINGLE QUANTUM-WELLS

Growth interruption-induced microroughness is studied by photoluminesc ence (PL) of single quantum wells with different well widths and inter ruption times. Analysis of the peak splitting in the PL spectra shows that the adjacent peak splittings correspond to well width differences smaller than one monolayer. The number of split peaks increases with increasing well width, saturating when the well width exceeds 11 monol ayers. This trend correlates well with the decrease in the lateral dim ension of the exciton, which corresponds roughly to the minimum optica lly sampled area of the interface. For a given quantum well, a plot of the normalized integrated intensities of the split PL peaks versus th e well width fluctuation is well described by a Gaussian distribution with an average fluctuation smaller than one monolayer. These results are consistent with the microroughness model.