High efficiency of CdSe quantum-dot-sensitized TiO2 inverse opal solar cells

Abstract

The authors have demonstrated an approach to sensitized-type solar cells, based on $\mathrm{Ti}{\mathrm{O}}_2$ inverse opal and the use of CdSe quantum dots (QDs) as sensitizers. CdSe QDs were grown in situ on $\mathrm{Ti}{\mathrm{O}}_2$ inverse opal electrodes, utilizing a chemical bath deposition method. All of the photovoltaic performances, including short circuit photocurrent density, open circuit voltage, fill factor, and efficiency, were significantly improved by surface modification with ZnS and fluoride ions. A power conversion efficiency of about 2.7% has been attained, under solar illumination of $100\mathrm{mW}∕{\mathrm{cm}}^2$ . This value is relatively high for metal oxide solar cells, sensitized with semiconductor QDs.