The stoichiometry and phase homogeneity of the kesterite type compound Cu2ZnSnS4 play a key role in its efficiency in solar cells. In this work, CuCl2, ZnCl2 and SnCl2 were applied...

A pure Cu2ZnSnSe4 phase was prepared from elemental Cu, Zn, Sn, and Se with the addition of a KI–KCl mixture.

In this work, Ga2S3 crystals were obtained by vertical Bridgman method. The presence of cracks in the grown crystals was interpreted as a result of phase transition into monoclinic structure during cooling. This suggests the use of another approach for the growth of high quality samples, e.g. chemical transport method or melt-solution method. Maximal transparency range of 0.48-22.5 μm and at least 10 times higher damage threshold to that for GaSe render anisotropic Ga2S3 crystal among the most prospective crystals for nonlinear applications.

In this work, a two-step method for preparation of CZTSe (Cu2ZnSnSe4) single crystals was demonstrated for the first time by recrystallization of a polycrystalline material in a KI-KCl melt-solution in a temperature gradient. At the first step, a polycrystalline material consisting of a mixture of metal selenides was synthesized by direct fusion of elemental Cu, Zn, Sn, and Se at 1000°C. Next, recrystallization process was carried out at a temperature gradient of 100°C, while the temperature of the cold zone was 750°C. The phase and chemical composition of the crystals were studied by energy dispersive X-ray and Raman spectroscopy. It was shown that the charge composition does not affect the composition of the obtained crystals. According to the amount of the remaining charge in the hot zone, one can speak of a very low recrystallization rate and a low product yield. Analysis of the elemental composition of crystals from the cold zone revealed a high inhomogeneity even in one experiment, which indicates the need to optimize the experimental parameters. On the other hand, according to the full line width at half height of the main peak, it can be argued that the obtained samples have a high degree of order in the structure and are suitable for measuring of physical characteristics.

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