We study an insulator-metal transition in a ternary chalcogenide glass (GeSe3)1−xAgx for x=0.15 and 0.25. The conducting phase of the glass is obtained by using "Gap Sculpting" (Prasai et al, Sci. Rep. 5:15522 (2015)) and it is observed that the metallic and insulating phases have nearly identical DFT energies but have a conductivity contrast of ~108. The transition from insulator to metal involves growth of an Ag-rich phase accompanied by a depletion of tetrahedrally bonded Ge(Se1/2)4 in the host network. The relative fraction of the amorphous Ag2Se phase and GeSe2 phase is shown to be a critical determinant of DC conductivity.
@article{arxiv.1703.02838,
title = {Amorphous to Amorphous Insulator-Metal transition in GeSe$_3$:Ag glasses},
author = {Kiran Prasai and Gang Chen and David Drabold},
journal= {arXiv preprint arXiv:1703.02838},
year = {2018}
}