Sensors Based on Radiation-Induced Diffusion of Silver in Germanium Selenide Glasses

In this study we demonstrate the potential radiation sensing capabilities of a metal-chalcogenide glass (ChG) device. The lateral device senses radiation-induced migration of ions in germanium selenide glasses by measuring changes in electrical resistance between electrodes. These devices exhibit a high-resistance ‘OFF-state’ (~1012 Ω) before irradiation, but following irradiation with either 60 Co gamma-rays or UV light, their resistance drops to a low-resistance ‘ON-state’ (~1013 Ω). The devices have exhibited cyclical recovery with room temperature annealing of Ag doped ChG, which suggests potential use in reusable radiation sensor applications. Furthermore, the mechanisms of radiation-induced Ag/Ag+ transport and reactions in ChG are modeled using a finite element device simulator. The essential reactions captured by the simulator are radiation-induced carrier generation, combined with reduction/oxidation for both ionic and neutral Ag species in the chalcogenide film. The results provide strong qualitative evidence that finite element codes can simulate ionic transport reactions in the ChG and reveal plausible mechanisms for radiation-induced metal doping