Functionally expanded phase-change memory: experiments on light influence on threshold voltage

We describe the first experimental results of a light influence on the threshold voltage V_t in new ternary lead-free telluride compound (labeled as SA1). Reduction of V_t on about 35% in SA1 illuminated by Ar ion laser to compare dark V_t is discovered. More than 10,000 switching cycles without degradation have been recorded. Variation of the laser power allows achieving V_t reduction in SA1 down to 40% from the dark level. This is the largest change of V_t known for amorphous chalcogenides. It opens new horizons for chalcogenide functionally expanded phase change memory. Some ideas about the mechanism of the observed effect, related with the photo-generation of charge carriers and possible mechanisms of transition from OFF state to ON state, are discussed