Abstract

The main feature of thin-film quasi-zero-dimensional structures is a high concentration of nanometer-sized microcrystallites (nanocrystals – NCs) and, as a result, the overall large area of the near-surface layer [1]. The existence of a large number of internal boundaries ‘NC—matrix’ in such media gives rise to the appearance of an additional (compared with the single-crystal) system of energy levels (surface state — SS), lying near the edge of the mobility band and playing the role of traps for free charge carriers. The additional coloring band of thin-film quasi-zero-dimensional structures shifts the absorption edge of the media into the long-wavelength region of the spectrum [1, 2] and, as predicted in [3], makes it possible to realize nonresonant electronic mechanisms for nonlinearity and photoluminescence owing to light-induced population of localized states.

© 1996 IEEE