Polycrystalline Cu2ZnSn(SхSe1– х)4 solid solutions have been prepared by a single-temperature method using elemental Cu, Zn, Sn, S, and Se. The chemical composition of the synthesized materials has been determined by X-ray microanalysis and their crystal structure and phase composition have been studied by X-ray diffraction and Raman spectroscopy. Using frequency-time-resolved microwave photoconductivity measurements, we examined the effect of sulfur and selenium content on photogenerated current carrier loss kinetics in the Cu2ZnSn(SхSe1– х)4 solid solutions. An increase in sulfur content has been shown to result in the formation of additional deep levels, capable of acting as electron acceptors.

The quaternary semiconductor compounds Cu2ZnSnSe4, Cu2ZnSiSe4, and Cu2ZnSn1 – xSixSe4 solid solutions on their basis have been synthesized from the elementary components Cu, Zn, Sn, Si, and Se by the single-temperature method. The room- temperature unit-cell parameters of the obtained compounds and solid solutions are determined by the X-ray method. It is established that two series of solid solutions are formed in the Cu2ZnSn1 – xSixSe4 system: one is based on the Cu2ZnSnSe4 compound with a tetragonal structure at x ≤ 0.5 and the other is based on the Cu2ZnSiSe4 compound with a orthorhombic structure at x ≥ 0.7.

The high-temperature orthorhombic phase of Cu 2 CdGeSe 4 quaternary compound, tetragonal phase of Cu 2 CdSnSe 4 compound, and Cu 2 CdGe x Sn 1 – x Se 4 solid solutions have been grown from elementary components Cu, Cd, Ge, Sn, and Se by one-temperature synthesis. The unit-cell parameters of the grown compounds and solid solutions have been determined by X-ray diffraction analysis at room temperature. It is shown that a continuous series of solid solutions, based on Cu 2 CdSnSe 4 compound, is formed in the Cu 2 CdGe x Sn 1 – x Se 4 system in the range of 0 ≤ х ≤ 0.8, and the Cu 2 CdGe x Sn 1 – x Se 4 system at x ≥ 0.9 is an orthorhombic crystalline phase.

The quaternary compounds Cu2ZnGeSe4, Cu2ZnSiSe4 and their solid solutions are synthesized from the elementary components Cu, Zn, Ge, Si, and Se by the single-temperature synthesis method. The unit-cell parameters of the synthesized compounds and Cu2ZnGe1 –xSixSe4 solid solutions are determined at room temperature by X-ray diffraction (XRD). It is shown that the unit-cell parameters a, b, and c decrease as x increases. It is found that two series of solid solutions are formed in the Cu2ZnGe1– xSixSe4 system: one is based on the Cu2ZnGeSe4 compound and the other is based on Cu2ZnSiSe4.

The high-temperature orthorhombic phase of Cu2CdGeSe4 quaternary compound, tetragonal phase of Cu2CdSnSe4 compound, and Cu2CdGexSn1 – xSe4 solid solutions have been grown from elementary components Cu, Cd, Ge, Sn, and Se by one-temperature synthesis. The unit-cell parameters of the grown compounds and solid solutions have been determined by X-ray diffraction analysis at room temperature. It is shown that a continuous series of solid solutions, based on Cu2CdSnSe4 compound, is formed in the Cu2CdGexSn1 – xSe4 system in the range of 0 ≤ х ≤ 0.8, and the Cu2CdGexSn1 – xSe4 system at x ≥ 0.9 is an orthorhombic crystalline phase.

Quaternary compounds (Cu 2 ZnGeSe 4 and Cu 2 ZnSnSe 4 ) and solid solutions on their basis are prepared via single-temperature synthesis from Cu, Zn, Ge, Sn, and Se. The crystallographic characteristics of the synthesized compounds and Cu 2 ZnGe x Sn 1 – x Se 4 solid solutions are determined using the X-ray diffraction method at room temperature. It is found that parameters a and c reduce with increasing Ge concentration.

The quaternary semiconductors Cu2CdSnS4, Cu2CdSnSe4 and Cu2CdSn(SxSe1–x)4 solid solutions were synthesized by the one-temperature method from the elementary components. The X-ray diffraction method showed that the obtained polycrystalline samples are single-phased. The unit cell parameters of the synthesized compounds and Cu2CdSn(SxSe1–x)4 solid solutions were determined from diffraction spectra by the full-profile analysis using the Rietveld method with the Fullprof software package. It has been established that with an increase in sulfur concentration, the unit cell parameters decrease smoothly linearly in accordance with the Vegard rule, which indicates the formation of a continuous series of solid solutions in the Cu2CdSn(SxSe1–x)4 system within the range 0 ≤ x ≤ 1. The parameter of crystal lattice tetragonal distortions h of the investigated compounds is calculated. The h values are close to 1 for all the compositions studied, which indicates a small crystal lattice distortion of the obtained samples.

The unit-cell parameters of crystals obtained in the Tl(GaS 2 ) 1– x (InSe 2 ) x system are measured by X-ray diffraction. The relationship between these parameters and composition is determined. It is shown that, with growing x , the a , b , and c parameters increase and the β angle decreases. Two types of solid solutions are found in the Tl(GaS 2 ) 1– x (InSe 2 ) x system: one is based on compound TlGaS 2 with monoclinic structure and the other is based on TlInSe 2 with tetragonal structure.

Quaternary compounds Cu2ZnSnS4 and Cu2ZnSnSe4 and solid solutions on their basis have been fabricated by one-temperature synthesis from elementary components: Cu, Zn, Sn, S, and Se. Single crystals of these compounds have been grown by the method of chemical gas-transport reactions from polycrystalline samples. The compositional dependence of the unit-cell parameters of Cu2ZnSn(S x Se1–x )4 has been investigated by X-ray diffraction. It is found that parameters a and c linearly decrease with an increase in sulfur concentration in accordance with Vegard’s law. The temperature dependences of parameters a and thermalexpansion coefficients α a of Cu2ZnSnS4 and Cu2ZnSnSe4 single crystals in the range of 100–300 K are determined.