Solution-processed method for high-performance Cu2ZnSn(S,Se)4 thin film solar cells and its characteristics

Abstract Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) has attracted much attention as an ideal absorber material for thin film solar cells. Solution deposition methods provide a crucial approach for lowering the fabricating price of CZTSSe based photovoltaic devices. Here, a low-cost and robust ethanol/thioglycolic acid/1-butylamine ternary solutions method was developed to fabricate the CZTSSe solar cells. Characterization was performed using XRD, Raman, and C–V, which showed that the material fabricated by this method expressed high-phase purity, suitable carrier concentration, and large depletion width, and those features are vital to high efficiency photovoltaic devices. Hence, based on this high quality CZTSSe absorbed layer, photovoltaic device with a power conversion efficiency (PCE) as high as 9.71% was achieved. The PCE can be further enhanced through passivating with alkali metal and optimizing the device fabrication conditions, making this method much promising for lowering the manufacturing cost of kesterite solar cells. Additionally, this approach is full of application prospect for other burgeoning photovoltaic absorber materials which could dramatically reduce the cost of solar electricity.