Fabrication of the protonated pentatitanate nanobelts sensitized with CuInS2 quantum dots for photovoltaic applications

• CuInS2 quantum dots are synthesized by solvothermal method.
• CuInS2 quantum dots are uniformly deposited on titanate nanobelt films.
• The absorption property of the titanate nanobelts is better than that of the TiO2.
• Titanate nanobelt has better electron–holes generation and separation than that of the TiO2.
• Photovoltaic efficiency of titanate nanobelt photoanode of 1.05% is better than that of TiO2 photoanode of 0.72%.

Titanate nanomaterials are considered to be the desirable materials for solar cells application because of their special optical absorption properties. In the present paper, protonated pentatitanate nanobelts prepared by hydrothermal method are used as photoanodes by screen-printing method. While CuInS2 quantum dots with the particle size of 3.5 nm are synthesized by solvothermal method and uniformly linked on the surface of the protonated pentatitanate nanobelt films by 3-Mercaptopropionic acid, which serves as the sensitizers in sensitized solar cells. The sensitization content of the quantum dots on the photoanode is determined by the number of preparative chemical linking cycles. The optical absorption of such sensitized pentatitanate nanobelt films enhances under the full solar spectrum, following with a red-shift of the absorption peak from 308 nm to 325 nm. Under AM 1.5 illumination, the best photovoltaic conversion efficiency of these structures using a sulfide/polysulfide redox electrolyte is about 1.05% following 8 preparative chemical linking cycles, which is better than that of TiO2 nanocrystalline photoanodes. This result suggests that these photoanodes may have the significant research prospects and potential application in solar cells.