Formation of CZT(S,Se) quaternary compounds nanoparticles by using melt quenching and PVD technique

Document Type : Research Paper


1 Department of Physics, College of Science, University of Diyala, Diyala, Iraq

2 Renewable Energy Directorate, ministry of science and technology, Baghdad, Iraq


Copper zinc tin sulfide and selenide (CZT(S,Se)) nanoparticles have been prepared using two-step procedure. The initial step started with the preparation of Cu2ZnSn(S,Se)4 powder using the melt quenching technique, and the second step is the fabrication of CZT(S,Se) thin films using the thermal evaporation deposition process. The obtained films were heat-treated at annealing temperatures of 50°C, 150°C, and 300°C. Atomic Force Microscopy (AFM), Field Emission Scanning Electron Microscopy (FE-SEM), X-RAY diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR) were used to characterize the samples. The XRD result showed that crystal structure of all of the films were polycrystalline kesterite phase. At 300 °C, CZTS film crystallite size was (9.8 nm) and for CZTSe film was (10.9 nm). The direct band gaps for CZTS and CZTSe were (1.95, 1.89 eV) respectively, at 50 °C; (1.90, 1.79 eV) respectively, at 150 °C; (1.87, 1.71 eV) respectively, at 300 °C, these results were estimated by Tauc’s equation. The energy gap of CZT(S,Se) materials is not far off the optimum value for greatest solar cell efficiency, AFM results revealed that when the size of the grain is directly proportional to the temperature, particles size and RMS of CZT(S,Se) film were increased as annealing temperature elevated. The functional groups are analyzed by using FTIR spectroscopy. Hall measurements revealed that all of the samples were p-type. The highest carrier concentrations were found 9.75×106 cm−3 for CZTS at 300°C and 6.72×106 cm−3 for CZTSe at the same temperature.