Giant photoplastic effect in vitreous semiconductors near the rigidity percolation transition

The negative giant photoplastic effect (giant photosoftening) has been experimentally observed in the As–Se system when films obtained by thermal evaporation of As$_{20}$Se$_{80}$ chalcogenide glass are irradiated by light from the region of the fundamental absorption edge. Correlation has been found between the photoplastic effect and rigidity percolation transition in the As–Se chalcogenide glass matrix. Such a correlation is not revealed when light irradiation changes the optical properties of these glass films. It has been shown that a nonlinear (non-Hookian) mechanism of the formation of the strain response is realized in the films subjected to the combined action of light and external mechanical loading.