Influence of Quantum Dot Concentration on Carrier Transport in ZnO:TiO₂ Nano-Hybrid Photoanodes for Quantum Dot-Sensitized Solar Cells

Francis S Maloney; Uma Poudyal; Weimin Chen; Wenyong Wang

doi:10.3390/nano6110191

Influence of Quantum Dot Concentration on Carrier Transport in ZnO:TiO₂ Nano-Hybrid Photoanodes for Quantum Dot-Sensitized Solar Cells

Nanomaterials (Basel). 2016 Oct 25;6(11):191. doi: 10.3390/nano6110191.

Authors

Francis S Maloney¹, Uma Poudyal², Weimin Chen³, Wenyong Wang⁴

Affiliations

¹ Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA. fmaloney@uwyo.edu.
² Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA. upoudyal@uwyo.edu.
³ Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA. wmchen@wit.edu.cn.
⁴ Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA. wwang5@uwyo.edu.

Abstract

Zinc oxide nanowire and titanium dioxide nanoparticle (ZnO:TiO₂ NW/NP) hybrid films were utilized as the photoanode layer in quantum dot-sensitized solar cells (QDSSCs). CdSe quantum dots (QDs) with a ZnS passivation layer were deposited on the ZnO:TiO₂ NW/NP layer as a photosensitizer by successive ion layer adsorption and reaction (SILAR). Cells were fabricated using a solid-state polymer electrolyte and intensity-modulated photovoltage and photocurrent spectroscopy (IMVS/PS) was carried out to study the electron transport properties of the cell. Increasing the SILAR coating number enhanced the total charge collection efficiency of the cell. The electron transport time constant and diffusion length were found to decrease as more QD layers were added.

Keywords: carrier transport; intensity modulated photovoltage spectroscopy; quantum dot sensitized solar cell.