Fundamental absorption and band gap of glasses S87-2, S78-4, S78-5

Abstract

In special glasses for electronic technology of brands S87-2, S78-4 and S78-5, the effect of thermal processes on the spectra of optical absorption in the wavelength range from 200 to 1100 nm was investigated. Glasses were studied both in the initial state and after annealing at various thermodynamic conditions: in an atmosphere of natural air and in vacuum at temperatures of 400 and 500°С, as well as in flow-through hydrogen at a temperature of 400°С. The influence of the medium, temperature and annealing time on the dispersion dependences of the absorption of the studied glasses was established. It was found that the time of absorption by some glass components has a significant effect on the own absorption of annealing in hydrogen. The edge of the fundamental absorption is determined and the width of the prohibited zone of the resulting nanocrystalline phases is estimated. The width of the prohibited zone of the nanocrystalline phases formed during the annealing of samples at high temperature, according to the results of optical measurements, is from 2,0 to 3,7 eV.

Keywords

• glasses
• intrinsic absorption
• nanocrystal
• band gap