Possibility of Anderson transition in semiconductor nanocrystal ensemble

Absorption spectrum of a quantum dot ensemble was Found to exhibit a system atic evolution with dot concentration from a set of discrete subbands inher ent in isolated nanocrystals to a smooth band-edge absorption similar to th at of bulk semiconductors. The results are interpreted in terms of the Ande rson transition which occurs in a system of close-packed nanocrystals with random deviations of positions from an ideal three-dimensional lattice. The proposed interpretation is confirmed by numerical calculations.