Incorporation of the TiO2 nanowire arrays photoanode and Cu2S nanorod arrays counter electrode on the photovoltaic performance of quantum dot sensitized solar cells

Abstract

Due to the one-dimensional single crystal array nanostructure and large surface area ratio, the TiO2 nanowire arrays and Cu2S nanorod arrays are prepared to be used as the photoanodes and counter electrodes in the quantum dot sensitized solar cells. It is observed that the diameters of TiO2 nanowire and Cu2S nanorod are 80nm and 100-150nm, respectively. The optical absorption of TiO2 photoanodes are obviously enhanced after the quantum dots deposition. The incident photon to current conversion efficiency spectra and electrochemical impedance spectroscopy indicate high electron transfer rate of TiO2 nanowire arrays and good electrocatalytic activity for polysulfide reduction and charge transfer of Cu2S nanorod arrays. Incorporating the TiO2 nanowire arrays photoanode and Cu2S nanorod arrays counter electrode, the CuInS2/CdS quantum dot sensitized solar cell achieves a photovoltaic power conversion efficiency of 4.13% under one-sunlight illumination, which is higher than that of the device based on TiO2 and Cu2S nanoparticle films (3.53%).