Threshold switching in hydrogenated amorphous silicon

Threshold switching is observed in n+-i-n+ sandwich structures of hydrogenated amorphous silicon after an initial forming process. At the threshold voltage the device switches from a low conductance to a high conductance state. The devices remain stable after more than 109 switching operations at a pulse frequency of 10 kHz. It is suggested that in the high conductance state filamentary conduction occurs in a permanent altered region created during the forming process.