The luminescent properties of a composite consisting of mesoporous silica and mercury diiodide nanoparticles formed in silica nanopores have been investigated. The formation of nanoparticles was carried out by evaporation of a HgI2 solution introduced into the SiO2 nanopores. It was found that photoluminescence of the HgI2@mSiO2 composite was due to emission of mercury diiodide, with the emission spectrum being significantly shifted towards shorter wavelengths with respect to the emission

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... um of bulk HgI2 crystals. The shift of the HgI2 emission spectrum to the short-wavelength side is explained by quantum-size effects in the electronic spectra of HgI2 nanoparticles included in the composite. The significant width of the spectrum is explained by its inhomogeneous broadening due to the dependence of the band gap of the nanodots on their size d. The shape of the size distribution function of HgI2 nanodots was estimated and it was shown that it was characterized by a rather narrow maximum at dM = 2.2 nm, which is 2/3 of the diameter of the nanopores in the SiO2 matrix (~3 nm).