Iron alloying improved electrocatalytic activity of Cu2Cu1-xFexSnS4 counter electrodes in dye-sensitized solar cells

Abstract

Abstract Nanocrystalline Cu2Cu1 − xFexSnS4 (CCFTS) was prepared by a simple liquid-phase method. Conduction band shifts as well as the bandgap increase were observed in the as-prepared CCFTS. For the dye-sensitized solar cells (DSSCs) with CCFTS counter electrodes (CEs), charge transfer impedance (Rct1) and short-circuit current (Jsc) were reduced by 64.54% and improved by 14.64% respectively compared with that with Fe-free Cu3SnS4 (CTS) CE. The enhancement of electron transfer through the CE/electrolyte interfaces indicates the improvement of electrocatalytic activity of the CEs for reduction of I3− to I−. As a consequence, photovoltaic conversion efficiency (PCE) of 6.95% was obtained which is 1.25 times that of the cell with Fe-free CTS CE.