Method for obtaining a multispectral grade of zinc sulfide
Wide-gap semiconductors of the A2B6 type are traditionally used in the manufacture of IR optics. A special place in this group is occupied by zinc chalcogenides ZnSe and ZnS, due to the combination of unique properties, as well as the proven technology for obtaining these materials by chemical vapor deposition. It should be emphasized that the resulting CVD-ZnS is a polycrystalline material, the size of microcrystals (grains) of which is a parameter controlled within known limits, which varies during production. ZnS grown by traditional CVD technology has insufficient transparency in the visible range. The limitation of transmission in this case is due to the scattering of radiation by optical microsized inhomogeneities formed during growth in the polycrystalline CVD-ZnS FLIR-grade material.
For a number of applications, opacity in the short-wavelength part of the spectrum is unacceptable. It is possible to improve the properties of polycrystalline zinc sulfide during its subsequent processing by the method of high-temperature isostatic pressing (HIP - Hot Isostatic Press). As a result of such processing, a material with the highest possible transmission in the entire spectral range of 0.4 - 13.5 μm is obtained. At the same time, the mechanical strength properties of CVD-ZnS FLIR-grade are also improved, due to a decrease in the number of optical microsized inhomogeneities in the volume, and structure ordering. The resulting material is called CVD-ZnS MS grade (MS - MultiSpectral).
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Vladimir State University named after Alexander and Nicolay Stoletovs
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