Photoelectrical properties of Ag2S quantum dot-modified TiO2 nanorod arrays and their application for photovoltaic devices

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 Jsc 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.