Semiconductor Hg3In2Te6 crystals and their analogous are solid solutions of In2Te3 and HgTe. Hg3In2Te6 crystals are congruently melted as chemical compound. Like In2Te3 the Hg3In2Te6 crystal has cubic crystal lattice with stoichiometric vacancies in their crystal structure. The electroconductivity, photoconductivity, mechanical, chemical properties of the crystals do not deteriorate after their irradiation by γ-photons with energies up to 1 MeV and doses up to 10^18 cm-2, by electrons with energies up to 300 MeV and doses up to 10^19 cm-2 and by mixed reactor irradiation (filtered slow neutrons) with doses up to 10^19 cm-2 [1,2]. This feature is determined by high concentration (~10^21 cm-3) of stoihiometric vacancies (Vs) in crystal structure, where every third In-cation node is empty. These Vs are electroneutral, they capture all impurity atoms in these crystals and kept them in electroneutral state too. On the other hand, this feature does not allow forming direct p-n junctions in these crystals by introducing the impurities. However, we have developed p-n junction analogues in form of Schottky diodes and corresponding photodiodes with semitransparent metal layer on single crystal Hg3In2Te6 substrate that allows irradiation to get into active region preserving this way all the advantages compared to p-n junction.