Light-driven ultrafast electric gating

Abstract

A source and drain electrode are spaced apart by an optically exposed gate region above a surface photovoltage effect (SPV) bulk. A two-dimensional material is deposited upon the gate region. The gate region is activated by exposure to an ultrafast light pulse, which may be infrared or near-infrared, and may be a focused collimated laser pulse with a sub-picosecond width. The pulse causes electron-hole pair generation resulting in band bending in the SPV material, which generates an electric field within the 2D material, thereby modifying the electronic properties between source and drain via a field-effect. After passage of the pulse, conduction continues in the device until the conductive electron-hole pairs recombine during the SPV decay time. The two-dimensional material may comprise a crystalline atomic monolayer. The activation is repeatable with subsequent pulses, resulting in the device cycling on and off within timescales less than 200 picoseconds.

Dependencies are inferred from the claim text.