Spray deposited copper zinc tin sulphide (Cu2ZnSnS4) film as a counter electrode in dye sensitized solar cells

Abstract

Stoichiometric thin films of Cu₂ZnSnS₄ (CZTS) were deposited by the spray technique on a FTO coated glass substrate, with post-annealing in a H₂S environment to improve the film properties. CZTS films were used as a counter electrode (CE) in Dye-Sensitized Solar Cells (DSCs) with N719 dye and an iodine electrolyte. The DSC of 0.25 cm² area using a CE of CZTS film annealed in a H₂S environment under AM 1.5G illumination (100 mW cm⁻²) exhibited a short circuit current density (J_SC) = 18.63 mA cm⁻², an open circuit voltage (V_OC) = 0.65 V and a fill factor (FF) = 0.53, resulting in an overall power conversion efficiency (PCE) = 6.4%. While the DSC using as deposited CZTS film as a CE showed the PCE = 3.7% with J_SC = 13.38 mA cm⁻², V_OC = 0.57 V and FF = 0.48. Thus, the spray deposited CZTS films can play an important role as a CE in the large area DSC fabrication.