Effect of Se percent on the properties of Cu₂FeSn(S,Se)₄ thin films prepared by Sol–gel method

Cu₂FeSn(S,Se)₄ (CFTSSe) thin films have been prepared using the Sol–gel method. As the Se increases, the diffraction peaks of CFTSSe shift towards smaller angles, and the lattice constant linearly in relation to the Se content. Meanwhile, Raman peaks exhibit a red-shift phenomenon, and SEM reveals a gradual decrease in grain size, which is consistent with the XRD results. By altering the Se ratio, the band gap of CFTSSe can be tunable in range of 1.10 to 1.69 eV. This tunability exhibits a non-linear relationship with Se content, which holds potential for the use of CFTS-based materials in photovoltaic devices application.