Ultralong Rutile TiO2 Nanorod Arrays with Large Surface Area for CdS/CdSe Quantum Dot-sensitized Solar Cells

• Chemically etched TiO2 nanorod arrays were prepared on FTO substrates.
• CdS and CdSe quantum dots were deposited on nanorod.
• Structure and optical property of TiO2 nanorods were well study.
• Deposition time of CdSe were optimized regulated for QDSCs.
• A relatively high current density was obtained.

By using hydrothermal method and post-etched with hydrochloric acid at high temperature, the ultralong TiO2 nanorod arrays (TNARs) for CdS/CdSe co-sensitized solar cells (QDSCs) were fabricated on fluorine-doped tin oxide (FTO) glass. Then CdS quantum dots (QDs) and CdSe QDs were deposited respectively on the as-prepared TNARs by successive ionic layer adsorption reaction (SILAR) and chemical bath deposition (CBD). The deposition time of CdSe and the etching time of TNARs were regulated to optimize the properties of energy conversion. The morphologies, crystal structure and optical prosperities of TNARs/CdS/CdS were characterized by SEM, TEM, XRD, EIS and UV-vis spectra. A thickness of 17.6 μm TNARs with large inner surface area was first used for sandwich-type ordered QDSCs, it is found that the Jsc reached the maximum value (17.22 mA cm−2) and the cell conversion efficiency obtained with Pt as counter electrode reached 2.66%.

Ultralong TiO2 nanorod arrays were grown on FTO substrates by hydrothermal process, which were further roughened by chemical etching. The enlarged inner surface area considerably contributed to the enhanced power conversion efficiency (1.10% v.s. 2.66%) of QDSCs sensitized by CdS and CdSe QDs.Figure optionsDownload as PowerPoint slide