Sensitivity mechanism of mercury ion chalcogenide glass sensors: tracer and surface spectroscoph studies

摘要

Sensitivity mechanism of mercury ion microsensors based on AgBr-Ag_2S-As_2S_3 thin filjs has been investigatged using ~(11)Ag tracer exchange experiments, x-ray photoelectron spectroscopy (XPS) and secondary neutral mass spectroscopy (SNMS). It was found that non-linear sensor response in Hg(NO_3)_2 s olutions is caused by at least two principal ptoential-generating processes: (i) Hg to Ag~+ ion exchange and (ii) chemical reactions at the membrane surfade involving silver and mercury species.