Mesoscopic nitrogen-doped TiO2 spheres for quantum dot-sensitized solar cells

Abstract The photovoltaic performance of quantum dot-sensitized solar cell (QDSSC) based on mesoscopic nitrogen-doped TiO 2 spheres prepared by solvothermal method was investigated. The results indicate that CdSe x S (1− x ) /CdSe QDSSC based on this mesoscopic nitrogen-doped TiO 2 spheres shows an energy conversion efficiency of 3.67%, which is higher than that of the undoped TiO 2 spheres (2.14%). The electrochemical impedance spectroscopy shows retards charge recombination is occurred on nitrogen-doped TiO 2 spheres photoanode. The improvement of the photovoltaic performance of QDSSC could be attributed to the retarding charge recombination, the acceleration of the transfer rate of electrons, higher quantum dots loading and enhanced light scattering in the N-doped TiO 2 spheres film. A higher photovoltaic performance could be expected for other QDSSC with this N-doped TiO 2 sphere material.