Effects of Multi-walled Carbon Nanotube Incorporation in ZnO Photoelectrode on the Efficiency of Dye-Sensitized Solar Cells

Abstract

Multi-walled carbon nanotubes (MWCNTs) are one-dimensional nanostructuredmaterials with many interesting properties such as high thermal and electrical conductivities.Our groups have recently demonstrated that the presence of MWCNT conductive scaffolds ina titanium dioxide-based photoelectrochemical cell can boost the photoconversion efficiencyby a factor of more than 1.3. Here, we report the effects of the incorporation of MWCNTsinto the ZnO active layer on the photocurrent-voltage (J-V) characteristics of dye-sensitizedsolar cells (DSSCs). Compared to the conventional ZnO electrode, the composite filmcontaining 0.05 wt.% MWCNTs increased the short-circuit photocurrent (Jsc), consequentlyenhanced the energy conversion efficiency (??) by a factor of approximately 1.42. Theenhancement of the solar energy conversion may be attributed to an increase of the electricalconductivity of ZnO film containing MWCNTs electrode.

Key words: dye-sensitized solar cells, carbon nanotube, front electrode, electrochemicalimpedance spectroscopy.