Patent attributes
A device includes a substrate with a tunnel barrier disposed on active region defined on the substrate, a monolayer of graphene disposed on the tunnel barrier, a dielectric material disposed on the graphene, and an electrode disposed over a region of the dielectric material. A first voltage is applied across the electrode and the graphene to adjust a Fermi level within the graphene to a Fermi level position within the valence band of the graphene based upon a predetermined emission wavelength. A current is injected into the graphene's conduction band to cause the graphene to emit a broadband hot electron luminescence (HEL) spectrum of photons peaked at the predetermined emission wavelength. The device may be configured as a vertical-tunneling light-emitting hot-electron transistor. The broadband HEL photon emission spectrum emanating from the graphene may be voltage-tunable within the electromagnetic spectrum from UV to THz.