Improved solar cell performance of Cu2ZnSnS4 (CZTS) thin films prepared by sulfurizing stacked precursor thin films via SILAR method

This paper describes an approach to using the successive ionic adsorption and reaction (SILAR) method for the synthesis of Cu2ZnSnS4 (CZTS), a highly promising thin film absorber material. This approach involves the preparation of stacked precursor thin films of Cu2SnS3 and ZnS by using the SILAR method with different stacking orders, such as Mo/Cu2SnS3/ZnS (CZTS-A) and Mo/ZnS/Cu2SnS3 (CZTS-B). These stacked precursor films were sulfurized at 575 °C for 1 h in a H2S (5%) + N2 (95%) atmosphere. The characteristics of the CZTS thin films prepared using stacked sulfide precursors are strongly dependent on the stacking orders in the precursor thin films. The influence of different precursor stacking orders on the structural, compositional, morphological and optical properties as well as the photoelectrochemical (PEC) performance of the CZTS thin films were studied. The best PEC performance of 1.81% was obtained with a maximum Jsc of 11.68 mA/cm2, Voc of 0.42 V and FF of 0.37 for the CZTS thin films based on the stacking order of Mo/ZnS/Cu2SnS3.