Synthesis and photovoltaic properties of CuInS2/CdS quantum dots co-sensitised TiO2 photo-anodes

The CuInS2 and CdS quantum dots co-sensitised solar cells are successfully fabricated to improve the photovoltaic performance. The CuInS2 quantum dots are adsorbed on the surface of TiO2 nanoparticles by assembly linking technique, and then the CdS quantum dots are deposited by successive ionic layer absorption and reaction technique. The absorption intensity is obviously enhanced and absorption edge is expanded to 800 nm after the co-sensitisation process. Under the irradiation of the simulated sunlight, the incident photon conversion efficiency (IPCE) spectra are also expanded to a longer wavelength, and the IPCE intensity reveals the maximum value of 53%. As a consequence, the photovoltaic power conversion efficiency is greatly enhanced to be 3.01%. It is mainly attributed to the better visible absorption performance from CuInS2 quantum dots and the quantum confinement reduction of the quantum dots in these co-sensitised solar cells.