Abstract: A three-dimensional graphene antenna includes a three-dimensional graphene radiation layer, a dielectric substrate, a metal layer and a feeder line. The three-dimensional graphene radiation layer is made from porous three-dimensional graphene. A preparation method of the porous three-dimensional graphene includes steps of preparing pressurized solid particles by pressurizing gas into solid micro particles, mixing the pressurized solid particles with a graphene oxide dispersion liquid, removing liquid nitrogen under high pressure and low temperature such that the graphene oxide flakes enwrap around the pressurized solid particles, obtaining a graphene oxide block containing the pressurized solid particles by extruding, sublimating the pressurized solid particles in the graphene oxide block into gas, forming holes in the graphene oxide block and annealing, thereby obtaining the three-dimensional graphene.

Abstract: The invention relates to a wide spectrum multi-band detection structure with selective absorption enhancement and its preparation method. The structure comprises a plurality of sub-pixel units capable of detecting incident light in different bands. Each sub-pixel unit is composed of a square well-shaped microstructure array and a metal lower electrode (2), a photosensitive layer (3) and an upper electrode (4) on the surface thereof. The size and array spacing of square well-shaped microstructures in different sub-pixel units are determined according to the detection bands of the sub-pixel units where they are located. The upper openings of the square well-shaped microstructures are hollow to form a resonant cavity, and the adjacent square well-shaped microstructures in the same sub-pixel unit form a resonant cavity, thus solving the problem that the detector structure in the prior art cannot simultaneously realize visible light-near infrared multi-band absorption enhancement detection.

Abstract: A photodetector based on PtSe2 and a silicon nanopillar array includes a PMMA light-transmitting protective layer, a graphene transparent top electrode, a silicon nanopillar array structure coated with few-layer PtSe2, and metal electrodes of the graphene transparent top electrode and the silicon nanopillar array structure. A method for preparing the photodetector includes steps of: preparing graphene with a CVD method; preparing a silicon nanopillar array structure through dry etching; coating few-layer PtSe2 on surfaces of the silicon nano-pillar array structure through laser interference enhanced induction CVD; preparing graphene transparent top electrode; and magnetron-sputtering metal electrodes. The photodetector prepared by the present invention has a detection range from visible light to near-infrared wavebands. The silicon nanopillar array structure enhances light absorption of the detector, so that the detector has high sensitivity, simple structure and strong practicability.