Dye sensitized solar cells using the electric field assisted spray deposited kesterite (Cu₂ZnSnS₄) films as the counter electrodes for improved performance

Kesterite (Cu₂ZnSnS₄) thin films are spray deposited under 0 V and 1500 V DC voltages and then treated with N₂+H₂S(5%) environment at 500 °C for 1 h for sulphurisation. The improvement in different properties like structural, optical, morphological and electrical occur in the kesterite films deposited under the electric field. The activation energy is also reduced for these films, after applying the DC voltage during the spray deposition. These improvements resulted in the enhancement of the catalytic properties of kesterite films for use as the counter electrodes in dye sensitized solar cells. Dye sensitized solar cell using the kesterite film as a counter electrode deposit under the applied voltage of 1500 V exhibits the power conversion efficiency of 4.93%, which is higher than that for the kesterite film deposit under the applied voltage = 0 V (3.77%). The power conversion efficiency of sulphurised kesterite films deposit at 0 V and 1500 V yield further improvement in the power conversion efficiency (6.58 and 7.67%, respectively).