The effects of shape and size nonuniformity on the absorption spectrum of semiconductorquantum dots

Abstract

The optical absorption coefficient of an inhomogeneous quantum dot system is calculatedanalytically and numerically. The quantum dots are approximated as spheres whosesurfaces constitute infinite potential barriers, with a size distribution described by aGaussian function. The effects of size nonuniformity on the optical absorption spectrum ofquantum dot systems are analysed. The effects of shape are also discussed through thecomparison of these results to those relating to cubic quantum dots. It is shown that theoptical absorption spectrum of spherical quantum dots depends strongly on the dotsize distribution and that, although the curves obtained for cubic and sphericalquantum dots with comparable volumes are similar, there are differences in therelative energy positions and relative intensities of the optical absorption peaks.