Phenomenology of γ-irradiation-induced changes in optical properties of chalcogenide semiconductor glasses: A case study of binary arsenic sulfides

Two methodological approaches to describe changes in the optical transmission spectra of chalcogenide semiconductor glasses induced by high-energy gamma-irradiation are considered at the example of glassy arsenic sulfides. The studied radiation-optical effects are ascribed to destruction-polymerization transformations, both intrinsic and related to surface oxidation. Direct-chronology ex-situ and backward-chronology in-situ measuring protocols can be utilized to parameterize them in glasses, while the former includes unresolved input from natural and radiation-assisted physical ageing in addition to mismatch between control and reference glasses. The reliable signature of intrinsic radiation-optical phenomenology unbiased by competitive input from oxidation and physical ageing is provided with in-situ measurements for the same irradiated glass. The developed approaches are probed for glassy As40S60 and As30S70, which demonstrate principally different responses on radiation-structural transformations and accompanied physical ageing. Critical assessment is given on misleading speculations ignoring intrinsic changes in view of competitive contribution from radiation-induced surface oxidation and thermally-assisted ageing. Stoichiometric As2S3, showing dramatic changes in optical transmission spectra, is nominated as canonical model object among chalcogenide glasses revealing highest sensitivity to gamma-irradiation. These methodological solutions are in excellent agreement with structure-modification criteria developed to parameterize compositional trends in radiation-optical response of chalcogenide glass.