Toxic-free surface level sulphur doped 1D Ti-O_x-S_y nanorods for superstrate heterojunction CZTS thin-film solar cells

摘要

Surface level sulphur (5) doped TiO2 nanorods (5-TNRs) were fabricated via toxic-free novel three-step processes such as low-temperature hydrothermal method followed by thermal evaporation (5 layer) and post-annealing (350 degrees C, 450 degrees C and 550 degrees C) techniques. Present work focuses on the comprehensive studies of surface level doping, structure, morphology and compositional properties of different temperature annealed S-TNRs for CZTS thin-film (Au/CZTS/S-TNRs/TNRs/FTO) solar cells. The oxidation states of incorporated 5 atoms in the TiO2 matrix were identified from X-ray photoelector spectroscopy (XPS) analysis. A reduction in bandgap for 350 degrees C annealed S-TNRs film was observed from UV-Vis spectroscopy. The electrical characteristics showed the fabricated solar cells strongly depend on the S-TNRs annealing temperature. Proposed technique would be useful in effective and controlled (surface level) doping of 5 atoms into any desired nanostructured metal oxides for optoelectronic applications and, further useful in fabricating cadmium (Cd) free buffer layer in chalcogenide solar cells.