Mathematical calculation of the boundary conditions for zinc sulfide-selenide formation in the hydroxide-hydrazine-thiourea-selenium system

Based on thermodynamic constants, the concentration limits of the initial zinc-containing salt and the range of pH values at which the depositions of ZnS and ZnSe without Zn(OH)2 are possible were calculated. The boundary conditions of the formation of the ZnSxSe1–x solid solution in the hydroxide-hydrazine-thiourea-selenium system were defined by the overlap area between the constructed ZnS and ZnSe formation zones. The task of complex intermolecular interaction between complexed zinc ions and two chalcogenizers in the working solution was solved on the basis of mathematical calculations. A sample of the ZnSxSe1–x film was deposited within the calculated area of its formation, which was confirmed by X-ray diffraction and elemental analysis.