An efficient Cu2Zn1−xInxSn(S,Se)4 multicomponent photocathode via one-step hydrothermal approach for thin film solar cell

Abstract

Substitution of the cation is a major focus to diminish the antisite defects and boost the photovoltaic properties of the Cu₂ZnSn(S,Se)₄ absorber. In the present study, a facile hydrothermal route was successfully implemented for the synthesis of Cu₂Zn_1−xIn_xSn(S,Se)₄ (x = 0.0 to 0.075 M) (CZITSSe) thin films for solar cells. The morphology of the CZITSSe was engineered from nanocubes to compact well grown nanoflowers like surface morphology. The improvement in the photocurrent (J_sc) from 3.09 to 4.26 mA cm⁻² associated with the photovoltage (V_oc) from 386 to 556 mV and accompanying improvement in the conversion efficiency (η %) from 1.96% to 4.82% were accomplished via Indium (In³⁺) ion incorporation. The composition CZITSSe (x = 0.075 M) showed exemplary photoelectrochemical behavior with a highest photoconversion efficiency (PCE) of 4.82%. Further, I–V performance of the deposited photocathode shows conversion efficiency of 2.01 to 5.12% as function of Indium ions incorporation. The improvement in PCE was mainly ascribed to improved crystal quality and suitable band gap energy. The EIS analysis demonstrates that the charge transfer resistance (R_ct) of the CZITSSe films was reduced with In³⁺ ion concentration. This work offers a one-step hydrothermal route that is a prominent way to develop an In³⁺ ion substituted Cu₂Zn_1−xIn_xSn(S,Se)₄ photoelectrode for competent solar energy harvesting.