Cu₂ZnSn(S,Se)₄ (CZTSSe) belongs to a family of I₂-II-IV-VI₄ quaternary chalcogenide semiconductors and is probably one of the most promising compounds in photovoltaic conversion of solar energy and in hydrogen evolution from water as a photoelectrode. Recently CZTSSe powder samples were prepared and studied. In contrast to polycrystalline thin films which contain usually second phases the powder samples show single phase and composition uniformity. It makes such samples quite attractive for the fundamental study. Also CZTSSe powder samples with deviation from stoichiometry or with varying degrees of structural disorder are interesting for study. Therefore, this project aims to obtain and research complex physical properties of CZTSSe powder samples to establish a correlation between the stoichiometry and degree of structural disorder and optical and electrical parameters. To achieve the goal mentioned above the following steps were done :

• the stoichiometric and off-stoichiometric CZTSSe powder samples with different range of structural disorder were grown by the solid state reaction method. The chemical composition of the obtained crystals was analyzed by EDAX method;
• electrical properties of the CZTSSe powder samples were characterized by the resistivity measurements;
• the photoluminescence (PL) spectra were investigated and the activation energies of the impurities in the band gap was determined;
• the Raman spectra in the samples wewe investigated.

The obtained fundamental results are of interest for physics and material science of the kesterite compounds and are useful for the development of new generation electronic devices.

Team: