Preparation and characterization of Cu2FeGeS4 thin-film synthesized via spray ultrasonic method − DFT study

• Published in: Materials letters 2020-09, Vol.275, p.128070, Article 128070
• Main Authors: Beraich, M., Shaili, H., Benhsina, E., Hafidi, Z., Mansouri, S., Taibi, M., Bentiss, F., Guenbour, A., Bellaouchou, A., Mzerd, A., Zarrouk, A., Fahoume, M.
• Format: Article
• Language: English
• Subjects: Absorptivity; Argon; Band gap; Copper; Cu2FeGeS4; Density functional theory; Energy gap; Glass substrates; Inert atmospheres; Materials science; Photovoltaic cells; Raman; Raman spectroscopy; Solar cells; Spectrum analysis; Spray; Thin film; Thin films; Ultrasonic methods; Ultrasonic testing
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2020.128070

•Tetraonal Cu2FeGeS4 (CFGS) thin films were synthesized for the first time.•The DFT study show a direct band gap.•Cu2FeGeS4 show p-type conductivity.•An optical band gap of 1.80 eV was obtained. Thin film of Cu2FeGeS4 (CFGS) has been obtained for the first time via spray ultrasonic deposition of Cu − Fe − Ge precursors (aqueous salt) onto glass substrate (Ts = 180 °C), followed by sulfurisation under inert atmosphere (500 °C − Argon+sulfur). X − Ray − Diffraction (XRD) and Raman spectroscopy analysis confirmed the formation of polycrystalline Cu2FeGeS4 (CFGS) with tetragonal structure. The presence of Cu − Fe − Ge − S was confirmed by Energy Dispersive X − rayAnalysis (EDX). The p − type conductivity was confirmed. The theoretical calculation based on the density functional theory (DFT) show a direct band gap. The experimental and theoretical optical band gap was found to be in the range of 1.72–1.8 eV with high absorption coefficient (>104cm-1) in the visible spectra. The obtained results will be a basis to develop this material in the field of photovoltaics.