Effect of Rotational Speed on Properties of Sol–Gel Spin Coated Cu2Fe0.5Co0.5SnS4 Thin Films for Solar Cell

This research has examined how the rotational speed affects the structural, morphological, and optical characteristics of the compound copper iron cobalt tin sulfide Cu2Fe0.5Co0.5SnS4 (CFCTS). CFCTS thin films were applied to a glass substrate using the straightforward spin coating method, with varying rotational speeds, and without the need for a sulfurization step. The result of X-ray diffraction revealed the tetragonal phase with preferential orientation as (112). The morphological surface become homogenous and dense with increase of rotational speed. The elementary analysis determined the presence of the important element Cu, Fe, Co, Sn, S, so stoichiometry of CFCTS thin films improved with increased of rotational speed. The direct band gap of the CFCTS thin films was demonstrated by the optical result. The increase in rotational speed from 2500 to 4000 rpm resulted in a reduction of the optical band gap in CFCTS thin films, attributed to the quantum confinement effect, decreasing from 1.38 to 1.05 eV. These results confirm that it is possible to use this CFCTS material as potential absorber in solar cells in order to generate renewable energy. Also, a very high conversion efficiency can be achieved under the ideal synthesis conditions for this material.