Photoelectrical properties of Ag2S quantum dot-modified TiO_2 nanorod arrays and their application for photovoltaic devices

摘要

Vertically aligned TiO_2 nanorod arrays (NRAs) modified with Ag_2S 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 TiO_2 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 Ag_2S QDs/TiO_2 NRAs photoelectrode has a promising application in solar cells.