Spray‐deposited carbon‐nanotube counter‐electrodes for dye‐sensitized solar cells

Abstract

Carbon nanotubes due to their catalytic properties are a promising alternative to platinum counter electrodes (CE) for dye‐sensitized solar cells (DSSC). In this study, counter electrodes were made from double‐walled carbon nanotube (DWCNT) ink using the spray printing technique and afterwards they were thermally treated at temperatures ranging from 120 to 300 °C. Morphology and structure was studied using scanning electron microscopy and Raman spectroscopy. DSSCs were constructed from titanium‐dioxide photoanodes and DWCNT counter electrodes cured at various temperatures. The current–voltage characteristics of DSSCs and their impedance spectra recorded under illumination have been studied and compared. The photoconversion efficiency (PCE) of the solar cell reached a maximum value of 4.59% when the carbon layer was thermally treated at 300 °C and is 16% higher than that registered for devices with a standard platinum counter electrode.