Abstract

The dependence of the glass-transition temperature ( T g ), Urbach-tail slope (Δ), and optical gap ( E 03) on the chemical composition in As-Se-Te glasses has been studied. It was found that both T g and Δ are compositionally invariant, while E 03 increases with increasing selenium content. It is supposed that softening of the studied glasses is controlled by the strength of the As-As bonds, a fraction of which is compositionally invariant. Similarly the As-As bonds broken during glass formation are supposed to be responsible for frozen-in potential fluctuations giving rise to the Urbach tail. Hence the As-As bonds and broken As-As bonds control both T g and Δ, which were found interrelated Δ ≈ 1.3 K B T g . On the other hand, the optical gap is controlled by anion substitution, and the E 03( x) dependence can be calculated using the virtual crystal model (VCM). The bowing parameter calculated using VCM has been found to be γ = 0.54 eV, in good agreement with experiment.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.