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

Abstract

Nanocrystalline Cu 2 Cu 1 − x Fe x SnS 4 (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 dyesensitized solar cells (DSSCs) with CCFTS counter electrodes (CEs), charge transfer impedance (R ct1 ) and short-circuit current (J sc ) were reduced by 64.54% and improved by 14.64% respectively compared with that with Fe-free Cu 3 SnS 4 (CTS) CE. The enhancement of electron transfer through the CE/electrolyte interfaces indicates the improvement of electrocatalytic activity of the CEs for reduction of I 3 − to I − . As a consequence, photovoltaic conversion e ciency (PCE) of 6.95% was obtained which is 1.25 times that of the cell with Fe-free CTS CE.