Electrically switchable graphene photo-sensor using phase-change gate filter for non-volatile data storage application with high-speed data writing and access

An electrically switchable graphene photo-sensor (SGPS) is proposed for multiple functional applications. SGPS is a dual-gate thin-film transistor with a graphene channel and a phase-change chalcogenide (GeSbTe) gate filter. This gate filter is switchable between the amorphous (optically transparent) and crystalline (optically non-transparent) phases by applying the gate biases. When the gate filter is switched to the amorphous/crystalline (a/c) phases, the SGPS will/not yield photo-current (I_pc) under a constant light source. By detecting the presence of I_pc, two data states can be read out so as to accomplish non-volatile data storage. SGPS can present a switching speed of ~50 ns between the a/c phases of GeSbTe and a data access speed as fast as 10 ns. SGPS shows very good 10-year data retention at 85°C and good endurance of >;10⁶ switching cycles between the a/c phases of the GeSbTe gate filter.