▎ 摘　　要

Sulfur and nitrogen co-doped graphene quantum dots (SNGQDs) were synthesized using a hydrothermal method. The doping of S, N atoms and chemical bonding in SNGQDs has been investigated by XPS measurements. Our as-grown SNGQDs showed strong UV (wavelength similar to 261-341 nm) and visible absorption (wavelength similar to 261-341 nm) and demonstrated excitation-dependent photoemission in visible spectrum. Photoelectrochemical and photovoltaic properties of SNGQDs sensitized carbon-doped ZnO nanotaper (C-ZnO NT) photoanodes has been studied in detail. SNGQD sensitized photoanodes demonstrated superior photoconversion efficiency (eta) similar to 1.46% and incident-photon-to-current conversion efficiency (IPCE) similar to 92.48% at 340 nm. Quantum dot sensitized solar cells (QDSSCs) has been fabricated using SNGQDs sensitized C-ZnO NT photoandoes and demonstrated maximum power conversion efficiency (eta(p)) similar to 0.59%.