Signatures of an extended rigidity percolation in the photo-degradation behavior and the composition dependence of photo-response of Ge–Te–In glasses

Time dependent photocurrent measurements have been undertaken on bulk $Ge₁₅Te_85-xIn_x (1 \leq x \leq 11)$ series of glasses. It is found that samples with x < 3 do not exhibit any photo-degradation whereas a decrease in photo-conductivity under illumination is observed in samples with $x\geq3$. Further, the photosensitivity of $Ge₁₅Te_85-xIn_x$ glasses is found to reveal specific signatures at compositions x = 3 and 7. The observed composition dependent photo-degradation behavior and photo-response of these glasses have been understood on the basis of an extended rigidity percolation and its influence on network related properties.