The Influence of Magnesium Doping on the Structural Characteristics of Cu₂ZnSnS₄ Nanoparticles Obtained by the Polyol Method

The work aimed for further application in photovoltaic and thermoelectric converters by synthesizing nanoparticles of magnesium-doped Cu<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>ZnSnS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> compound using the polyol method. The obtained samples were investigated using X-Ray, SEM, TEM, and optical spectrophotometry methods. It was found that magnesium doping leads to an increase in the size of synthesized nanoparticles and the lattice period of the material. It was demonstrated that a high concentration of magnesium (40%) resulted in a significant increase in dislocation density in the material, reaching values of $\rho_{\mathrm{L} \varepsilon}(116)=13.9 \cdot 10^{-16} \mathrm{lin} / \mathrm{m}^{2}$. The analysis of transmission spectra indicates a decrease in the bandgap width of the compound from 1.49 eV to 1.07 eV (C $\mathrm{Cmg}^{\prime}$ $=40 \%$) with an increase in Mg concentration, which then rises to $1.27 \mathrm{eV}\left(\mathrm{C}_{\mathrm{Mg}}=\mathbf{6 0 \%}\right)$.