Efficient Visible Spectrum Sensitization of BaSnO₃ Nanoparticles with N719

BaSnO 3 nanoparticles and (Bu 4 N) 2 (Ru)(dcbpyH) 2 (NCS) 2 (called N719)-sensitized BaSnO 3 nanoparticles were prepared by the sol−gel method. The structures and optical absorption spectra of the samples were examined with X-ray diffraction and UV−vis diffuse reflectance spectroscopy, respectively. Surface photovoltaic properties of the samples were investigated by surface photovoltage spectroscopy and electric field-induced surface photovoltage spectroscopy. The results indicate that N719 can enhance the photovoltaic response as well as extend the photovoltaic response range of BaSnO 3 nanoparticles to the visible region, which shows potential application in harvesting solar energy and future photovoltaic technology. The transfer of charge carriers between the dye and the semiconductor accounts for this photosensitization phenomenon. Valence-band spectra prove that the relative energy levels of N719 and the as-prepared BaSnO 3 nanoparticles fit well with the energy requirements for efficient electron injection.