Tailoring of nanocrystal sizes in CdSe films prepared by chemical deposition

We report on the control of nanocrystal sizes in nanocrystalline films of C dSe prepared by chemical solution deposition. We studied the effect of grow th duration, of the light illumination during the growth, and of subsequent heat treatment of the films. Nanocrystals with radii from 1.9 to 10 nm wer e prepared and characterized by transmission electron microscopy, X-ray dif fraction, and optical photoluminescence and absorption spectroscopy. We hav e observed the cubic and hexagonal structure for small and large nanocrysta ls, respectively. We interpret the trap-related photoluminescence in nanocr ystals in terms of recombination of a deeply trapped hole with an electron in an interior slate or in a shallow trap. (C) 2000 Elsevier Science B.V. A ll rights reserved.