Ultraviolet, infrared and terahertz photo/radiation sensors using graphene layers to enhance sensitivity

摘要

Ultraviolet (UV), Terahertz (THZ) and Infrared (IR) radiation detecting and sensing systems using graphene nanoribbons and methods to making the same. In an illustrative embodiment, the detector includes a substrate, single or multiple layers of graphene nanoribbons, and first and second conducting interconnects each in electrical communication with the graphene layers. Graphene layers are tuned to increase the temperature coefficient of resistance to increase sensitivity to IR radiation. Absorption over a wide wavelength range of 200 nm to 1 mm are possible based on the two alternative devices structures described within. These two device types are a microbolometer based graphene film where the TCR of the layer is enhanced with selected functionalization molecules. The second device structure consists of a graphene nanoribbon layers with a source and drain metal interconnect and a deposited metal of SiO2 gate which modulates the current flow across the phototransistor detector.

主权项

1. A graphene based microbolometer comprising:
a thin film of graphene suspended between electrical contacts; first and second conductive terminals in electrical communication with the thin film of graphene; and wherein the thin film of graphene is tuned such that exposure of radiation induces a change in impedance between the first and second conductive terminals which is sensed by CMOS readout circuitry; wherein the thin film of graphene is tuned to increase the sensitivity of the detector by increasing the density of bundled carbon nanotubes in the graphene film, which thereby increases the thermal coefficient of resistance (TCR) to excess of 4 percent per degree centigrade, thereby resulting in a Noise Equivalent Delta Temperature (NEDT) of less than 10 mK.