Structure and optical properties of Cu_xO- and Cu_xSe-doped sol-gel silica glasses

Copper oxide and copper selenide nanoparticles were produced within the silica glasses through the sol-gel technique. Chemistry of these copper compounds (variability in stoichiometry and copper oxidation state) provides a variety of optical properties of nanoparticles composed from them. A series of glasses with the nanoparticles different in stoichiometry was fabricated. The linear absorption spectra reveal the changes of the fundamental absorption edge position and appearance of the intense absorption band in the near IR. Photoluminescence is observed both for copper oxide and copper selenide nanoparticles evidencing Cu(I) states.