Photoinduced changes of the rate of dissolution of bilayer films of chalcogenide glasses

The change of the rate of dissolution upon the exposure of bilayer As39S61/As36S44Se20 films to light of wavelength 380 nm and more than 470 nm from the sulfo-selenide layer side has been investigated. Although light of wavelength 380 nm is absorbed in the first layer, in the second layer photoinduced structural changes are observed, which are assumed to occur as a result of the diffusion of electron-hole pairs from the illuminated selenium-containing layer to the nonexposed arsenic sulfide in contact. The excess charge carriers induce structural changes in the As39S61 film that are registered as dissolution rate changes. The calculated value of the drift mobility of the slowest charge carriers (electrons) of 10−11 cm2/(V s) is in agreement with the literature data. Studies of the Raman spectra of the films of interest confirmed that the diffusion of excess electrons and holes into the sulfide layer resulted in structural changes that manifested themselves in a decrease in the intensities and widths of the bands corresponding to vibrations of structural groups containing homopolar bonds.