▎ 摘　　要

NOVELTY - Photodiode comprises semiconductor substrate (110), insulating layer (120) formed on semiconductor substrate, electrode (130) formed on the insulating layer, graphene (140) formed on the semiconductor substrate, the insulating layer, and electrode, where the insulating layer comprises an ion gel. USE - Photodiode used in photodetector device (claimed). ADVANTAGE - The photodiode improves the photoresponse and detectability. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing photodiode, which involves forming an insulating layer on a semiconductor substrate, forming an electrode on the insulating layer and forming graphene on the semiconductor substrate, the insulating layer, and the electrode, where the insulating layer includes an ion gel. DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a photodiode. Semiconductor substrate (110) Insulating layer (120) Electrode (130) Graphene (140)