Facile hydrothermal synthesis of economically viable VO 2 (M1) counter electrode for dye sensitized solar cells

Abstract In this study, we focus at reducing the fabrication cost of dye sensitized solar cells (DSSCs). Sphere-like VO 2 (M1) polymorph was synthesized by single step facile hydrothermal approach using citric acid as the reducing agent. Phase purity, charge state and surface morphology of the synthesized product were confirmed by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy respectively. The electrochemical impedance and cyclic voltammograms of VO 2 films indicated a good electrocatalytic activity towards redox reaction of the I ⿿ /I 3 ⿿ shuttle. Owing to the low cost, low-temperature processing and good catalytic activity, in this work we propose to use VO 2 as a counter electrode to substitute the expensive platinum electrode in DSSCs. By means of VO 2 based DSSCs we achieved a fivefold reduction in the cost to energy conversion efficiency ratio. It is expected that with further optimization, VO 2 can be exploited as a good candidate for counter electrode in DSSC technology.