High-Performance TiO2/ZnO Photoanodes for CdS Quantum Dot-Sensitized Solar Cells
Abstract
High-performance TiO2/ZnO nanorod (NR) arrays were investigated for CdS quantum dots (QD) sensitized solar cells (QDSSCs). Well vertically aligned TiO2 nanotubes (NAs) were prepared by anodic oxidation, then TiO2/ZnO nanocomposite was accordingly obtained by a hydrothermal reaction. The TiO2/ZnO nanocomposite was further sensitized by CdS QDs as via successive ionic layer adsorption and reaction. Additionally, the ZnO NRs not only suppresses the recombination of photogenerated carriers by passivating the surface recombination sites in TiO2 NAs and forming an energy barrier between the ZnO and TiO2, but also enhances light absorption in the visible light region by facilitating the deposition of CdS QDs. As a result, the power conversion efficiency of QDSSC with the optimized TiO2/ZnO photoelectrode (0.33%) was enhanced by 278% and 164% compared with those of cells based on TiO2 NAs and ZnO NRs photoelectrode, which indicates the excellent performance of novel TiO2/ZnO structures as a photoanode. The power conversion efficiency of QDSSC with the optimized TiO2/ZnO/CdS photoelectrode (2.71%) increase by nearly 821% compared with that of cells based on TiO2/ZnO photoelectrodes. Energy band diagram of TiO2/ZnO photoanode and the J–V curves of QDSSCs with the TiO2/ZnO/CdS photoelectrodes (the highest η value of 2.71%).
- Publication:
-
Journal of Electronic Materials
- Pub Date:
- November 2019
- DOI:
- 10.1007/s11664-019-07536-5
- Bibcode:
- 2019JEMat..48.7320Z
- Keywords:
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- CdS quantum dots;
- ZnO nanorods;
- TiO<SUB>2</SUB> nanotubes;
- photostability;
- photovoltaic performance