Preparation of a CeO₂ ball-core structure and its application in quantum dot sensitized solar cells

A pomegranate-like nanosphere structure of CeO₂ was prepared by a simple one-step hydrothermal method, and the novel CeO₂ structure was printed on a TiO₂ film to form a scattering layer, which constituted the composite structure of a photoanode in a thin film optoelectronic device. Then ZnCuInSe quantum dots, a ZnS passivation layer and a CuS counter electrode were prepared, and these parts were assembled into quantum dot-sensitized solar cells. By changing the thickness of the scattering layer film in the photoanode, the quantum dots were adsorbed on TiO₂ more effectively. By using the special ball-core structure, light was scattered so that the photoanode used the light many times, which effectively increased the efficiency of photoelectron production. After electrochemical testing of the device, it was found that the photoconversion efficiencies of the TiO₂ transparent layer and the CeO₂ scattering layer composite photoanode were greater than that of a single TiO₂ photoanode without a scattering layer. The results showed that when the thickness of the scattered layer was 10 ± 1 μm, the highest photoelectric conversion efficiency (PCE) was obtained, which was 20% higher than that seen with TiO₂ alone.