▎ 摘　　要

NOVELTY - Germanium nano-pillar photodetector decorated with metal nanoparticles (4) has a bottom electrode (1), an intrinsic germanium substrate layer (2), and multiple germanium nano-pillar (3), which are periodically arranged on the insulating substrate layer. The germanium nano-pillars are provided with metal nanoparticles on the surface, and the work function of the metal is greater than 4.46eV. Graphene electrode (6) is covered on the multiple of germanium nano-pillar, and is separated from the intrinsic germanium substrate layer by a non-conductive dielectric material (5). The diameter of the metal nanoparticles is 10-100 nanometers. USE - Germanium nano-pillar photodetector decorated with metal nanoparticles for use in ray measurement and detection, industrial automation, photometry. ADVANTAGE - The detector has small dark current, high photocurrent and response degree, and high detection performance. The detector realizes Mie scattering and light local effect in a device to improve light absorption coefficient of the detector, thus enhancing response degree of the photoelectric detector. The metal nano-particles of the surface nano-pillars are adhered to the surface of the intrinsic germanium substrate layer, so that the surface ratio of the germanium material in the detector can be improved, thus correspondingly increasing series resistance between the graphene electrode and the bottom electrode, and hence effectively reducing the dark current of the photodiode, and improving sensitivity of the photosensitive detector. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a preparation method of germanium nano-pillar photodetector decorated with metal nanoparticles, which involves: (1) making bottom electrodes on the lower surface of germanium substrate; (2) depositing a non-conductive dielectric material on the upper surface of the germanium substrate; (3) etching a target area of the dielectric material to expose the germanium substrate below the target area; (4) etching the upper portion of the exposed portion of the germanium substrate to form a multiple of germanium nano-pillars; (5) periodically arranging multiple of germanium nano-pillars on the intrinsic germanium substrate layer. DESCRIPTION OF DRAWING(S) - The drawing shows a three-dimensional structure schematic view of the germanium nano-pillar photodetector decorated with metal nanoparticles. Bottom electrode (1) Intrinsic germanium substrate layer (2) Multiple germanium nano-pillar (3) Metal nanoparticles (4) Non-conductive dielectric material (5) Graphene electrode (6)