The effect of B2O3 additive to ZnS and ZnS-Ge system on their properties and parameters of thin-film coatings obtained from them has been studied. The essence of the additive is the binding of ZnO in Zinc sulfide, which has a negative effect due to the interaction with the evaporator material. According to X-ray diffraction, the introduction of B2O3 additive to ZnS results in the disappearance of the wurtzite phases (β-ZnS and ZnO). There is also a change in the IR spectra, in which reveal the bands at ≈300 cm−1 and 415 cm−1, which correspond to the valence vibrations of the Zn-S and Zn-O bonds, respectively. It is established that the addition of B2O3 noticeable improves the technological mode of evaporation in vacuum of materials due to the increase of their volatility. The reflection spectra of thin films of undoped and doped ZnS indicate a certain increase in the refractive index of the latter, while in the ZnS-Ge system such a difference is not observed. The mechanical durability of coatings increases especially significantly - more than 10 times for ZnS and more than 2 times - for the ZnS-Ge system. Therefore, the use of B2O3 as an additive has proved to be an effective method for minimizing the effects of oxide impurities in chalcogenide materials on the properties of thin-film coatings.