Why are chalcogenide glasses the materials of choice for Ovonic switching devices

摘要: Abstract Non-destructive switching from a high resistance OFF state to highly conducting ON occurs at critical field between 0.5 and 0.7 MV/cm in thin films of chalcogenide glasses placed two non-reacting contacts as discovered by S.R. Ovshinsky the 1960s. The device returns its original when current falls below holding value. We present theory this electronic state, which allows many billion reproducible cycles. In particular question is addressed why unique properties defect chemistry lead non-destructive effect. It proposed that initiated modified Zener tunneling breakdown. most voltage drop near electrodes confined filament. density supplied Fowler–Nordheim emission contacts. This made possible narrowness potential barriers turn consequence glasses. Electronic also observed Ovonic memory devices having preferred composition Ge 2 Sb Te 5 . large atomic sizes result partial 3-fold covalent coordination might affect related