Nanostructured TiO₂ sensitized with CuS quantum dots for solar energy conversion

The present paper contains the preparation of QDs sensitized on TiO₂ thin film as a photoanode for solar cell applications. The photoanode is developed by copper sulfide quantum dots (CuS QDs) on TiO₂ thin films using the successive ionic layer adsorption and reaction (SILAR). CuS QDs act as sensitizer because of its strong visible light absorption. Fabrication process comprises sensitizing CuS QDs on the surface of TiO₂ thin films controlled by 5 and 10 SILAR cycles. XRD study indicates the crystallite size of TiO₂/CuS QDs thin films is 11.6 and 13.7 nm for 5 and 10 cycles (cys), respectively. The outcome of UV-DRS and photoluminescence indicates the enhanced light absorption, reduction in bandgap and suppression of electron–hole pair recombination. The HR-TEM image revealed that the diameter of the TiO₂ is 10 nm and surroundings core-like CuS particles are observed. The TiO₂/CuS QDs (10 cys) configuration showed a better photoelectrochemical efficiency of 2.55% at 30 mW cm⁻² light intensity.