An optically-gated transistor comprised of amorphous M+Ge2Se3 (M=Cu, Sn) for accessing and continuously programming a memristor

摘要： We demonstrate that a device comprised of sputtered amorphous chalcogenide Ge2Se3/M+Ge2Se3 (M = Sn or Cu) alternating layers, functions as an optically-gated transistor (OGT) and can be used as an access transistor for a memristor memory element. This transistor has only two electrically connected terminals (source and drain), with the gate being optically controlled, thus allowing the transistor to operate only in the presence of light (385 – 1200 nm). The switching speed of the OGTs is less than 15 μs. The OGT is demonstrated in series with a Ge2Se3+W memristor, where we show that by altering the light intensity on the OGT gate, the memristor can be programmed to a continuous range of non-volatile memory states using the saturation current of the OGT as a programming compliance current. By having a continuous range of non-volatile states, one memory cell can potentially achieve 2n levels. This high density, combined with optical programmability, enables hybrid electronic/photonic memory.