Investigation of photoelectrical properties of CdSe nanocrystals embedded in a SiO2 matrix

CdSe nanocrystals (NCs) embedded in SiO2 thin films were prepared using RF-magnetron co-sputtering. The average NC size was estimated to be 18 nm. The dark and photocurrent temporal dependences have been measured as a function of the magnitude of applied voltage (50-150 V). Annealing the samples seems to improve the photoconductivity (∼10-12 Ω-1) that increases with the film thickness and slightly changes under the bias voltage. Furthermore, the photovoltage measurements showed that a concentration of CdSe in the range of 27 mol% leads to the generation of a photovoltaic signal up to 5 V at 400 μW cm-2. These results demonstrate the potential of silica films with embedded CdSe NCs for photovoltaic applications. © 2008 IOP Publishing Ltd.