Threshold conductivity switching in sulfurized antimony selenide nanowires

Abstract

We report reversible switching between Ohmic and negative differential resistance states at a threshold voltage in sub-100-nm diameter sulfurized antimony selenide nanowires. We show that threshold switching in our nanowires arises due to high non-equilibrium free carrier concentrations resulting from impact ionization of carriers from defect states traceable to sulfurization and surface dangling bonds. Threshold switching is suppressed because of inhibited carrier generation at air-passivated defect states or at high temperatures due to thermally induced carrier depletion from deep states which preempts impact ionization. Such non-linear phenomena would be important for designing phase-change memories, thermoelectric devices, and sensors using pnictogen chalcogenide nanowires.