Boosting the photovoltaic performance of Zn ₂ SnO ₄ ‐based dye‐sensitized solar cells by Si doping into Zn ₂ SnO ₄

In the present work, Zn 2 SnO 4 nanoparticles were doped with silicon to improve their electrical and optical properties by the conventional solid‐state reaction method. The results showed that the minimum electrical resistivity of about 0.09 Ωcm was obtained for Zn 2 SnO 4 nanoparticles with 3% Si doping. The decrease in the electrical resistivity can be attributed to the insertion of Si +4 atoms into the Zn +2 and/or Sn +4 sites and also the formation of more oxygen vacancies in the Zn 2 SnO 4 lattice. The formation of the more oxygen vacancy defect states in Si‐doped Zn 2 SnO 4 nanoparticles was verified by photoluminescence spectroscopy. The efficiency of a dye‐sensitized solar cell based on 3% Si‐doped Zn 2 SnO 4 was significantly better, by about 81%, compared to that of a cell based on the undoped Zn 2 SnO 4 . The enhancement in the efficiency can be ascribed to the facilitation of electron transport throughout a photoelectrode due to increase in the charge carrier concentration which was caused by Si doping.