▎ 摘　　要

NOVELTY - The device (100) has a top graphene layer (101a) that is formed of graphenes. A first electrode (103a) is deposited on an edge of the layer. The first electrode and a second electrode (103b) are so aligned to prevent short circuit through the liquid crystal or piezocrystal layer and a top surface of top graphene layer and a bottom surface of a bottom graphene layer (101b) are each covered by a layers of dielectric material (104a,104b) which are glass, silicon, magnesia, sapphire or polymer. USE - Graphene-based terahertz device for use in commercial applications. ADVANTAGE - The graphene-based THz device that is operated at an unexpectedly low direct current (DC) voltage when used as a THz phase shifter and unexpectedly low insertion loss when used as a THz modulator is provided. A high-performance THz phase shifter and THz modulator is developed. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method of preparing a graphene-based terahertz device. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a graphene-based THz device. Graphene-based terahertz device (100) Top graphene layer (101a) Bottom graphene layer (101b) First electrode (103a) Second electrode (103b) Layers of dielectric material (104a,104b)