POTENTIAL-DEPENDENT ELECTRON INJECTION IN NANOPOROUS COLLOIDAL ZNO FILMS

We have quantitatively investigated the charging of colloidal ZnO film s by cyclic voltammetry and potential step measurements. Up to six ele ctrons can be stored on each colloidal particle of the film (mean part icle diameter 5.9 nm) before zinc reduction occurs. Fluorescence and a bsorbance of the films are already strongly influenced in potential re gions where less than one electron is stored on each particle. Potenti ostatically controlled and time-resolved photocurrent measurements sho w the influence of trap filling as well as the role of the electrolyte on the charge transport through the films.