p-type graphene film/n-type Ge schottky junction near-infrared photoelectric detector and preparation method thereof

The invention discloses a p-type graphene film/n-type Ge schottky junction near-infrared photoelectric detector and a preparation method thereof. The p-type graphene film/n-type Ge schottky junction near-infrared photoelectric detector is characterized in that an n-type Ge substrate is used as a base region of a near-infrared photoelectric detector, and an n-type Ge substrate electrode is arranged on the lower surface of the n-type Ge substrate; the upper surface of the n-type Ge substrate is covered with an insulating layer, and the insulating layer does not go beyond the border of the n-type Ge substrate; the insulating layer is covered with a graphene contact electrode, and the graphene contact electrode does not go beyond the border of the insulating layer; and a p-type graphene film is laid on the graphene contact electrode, wherein a part of the p-type graphene film forms ohmic contact with the graphene contact electrode, the rest of the p-type graphene film forms schottky contact with the part, not covered with the insulating layer, of the upper surface of the n-type Ge substrate, and the p-type graphene film does not go beyond the border of the n-type Ge substrate electrode. The near-infrared photoelectric detector disclosed by the invention has the beneficial effects of large switch ratio, fast response speed and low dark current noise.