Facile hydrothermal synthesis of economically viable VO₂(M1) counter electrode for dye sensitized solar cells

In this study, we focus at reducing the fabrication cost of dye sensitized solar cells (DSSCs). Sphere-like VO2(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 VO2 films indicated a good electrocatalytic activity towards redox reaction of the I−/I3− shuttle. Owing to the low cost, low-temperature processing and good catalytic activity, in this work we propose to use VO2 as a counter electrode to substitute the expensive platinum electrode in DSSCs. By means of VO2 based DSSCs we achieved a fivefold reduction in the cost to energy conversion efficiency ratio. It is expected that with further optimization, VO2 can be exploited as a good candidate for counter electrode in DSSC technology.