Photoelectrical properties of Ag2S quantum dot-modified TiO2nanorod arrays and their application for photovoltaic devices

Abstract

Vertically aligned TiO₂ nanorod arrays (NRAs) modified with Ag₂S quantum dots (QDs) have been successfully prepared via a successive ionic layer adsorption and reaction (SILAR) process. Ultraviolet-visible (UV-vis) absorption spectra and surface photovoltage (SPV) measurements reveal that the Ag₂S sensitization extends the range of the photoresponse of the TiO₂ NRAs to the visible region and exhibits higher photovoltage responses. With a polysulfide electrolyte, a maximum conversion efficiency of 0.148% with a superior J_sc of 1.177 mA cm⁻² are obtained after 6 SILAR cycles under illumination at 100 mW cm⁻². These results indicate that the Ag₂S QDs/TiO₂ NRAs photoelectrode has a promising application in solar cells.