Summary: | Size controllable TiO<sub>2</sub> hollow microspheres (HMS) were synthesized by a carbonaceous spheres (CS) template method. Based on TiO<sub>2</sub> HMS, the ZnS/CdS quantum dots (QDs) were loaded to form a ZnS/CdS@TiO<sub>2</sub> HMS photoanode for quantum dots sensitized solar cell (QDSSC). The size effects of TiO<sub>2</sub> HMS on photovoltaic performance were investigated, and showed that TiO<sub>2</sub> HMS with sizes ~560 nm produced the best short-circuit current density (J<sub>sc</sub>) of 8.02 mA cm<sup>−2</sup> and highest power conversion efficiency (PCE) of 1.83%, showing a better photovoltaic performance than any other QDSSCs based on TiO<sub>2</sub> HMS with size ~330 nm, ~400 nm, and ~700 nm. The improvement of photovoltaic performance based on ~560 nm TiO<sub>2</sub> HMS which can be ascribed to the enhanced light harvesting efficiency caused by multiple light reflection and strong light scattering of TiO<sub>2</sub> HMS. The ultraviolet-visible (UV-vis) spectra and incident photo to the current conversion efficiency (IPCE) test results confirmed that the size of TiO<sub>2</sub> HMS has an obvious effect on light harvesting efficiency. A further application of ~560 nm TiO<sub>2</sub> HMS in ZnS/PbS/CdS QDSSC can improve the PCE to 2.73%, showing that TiO<sub>2</sub> HMS has wide applicability in the design of QDSSCs.
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