▎ 摘　　要

NOVELTY - A dual-mode broadband photodetector comprises planar silicon with insulating layer on its surface, as substrate, pair of first metal thin film electrodes provided on the insulating layer, detector window, which is formed by etching a portion of the insulating layer between the first metal thin film electrodes and exposing the planar silicon, passivation layer provided on the detector window and single layer of fluorinated graphene, which is coated on the passivation layer, where two ends of the fluorinated graphene form an ohmic contact with the first metal thin film electrode respectively, such that attaining construction of photoconductive type photodetector and second metal thin film electrode is coated on back side of the planar silicon and fluorinated graphene forms heterojunction with the planar silicon, such that attaining construction of silicon/fluorinated graphene photodiode type photodetector. USE - Dual-mode broadband photodetector. ADVANTAGE - The dual-mode broadband photodetector has wide spectral response range and excellent performance and is prepared in a simple manner and compatible with existing semiconductor processes. DETAILED DESCRIPTION - A dual-mode broadband photodetector comprises planar silicon with insulating layer on its surface, as substrate, pair of first metal thin film electrodes provided on the insulating layer, detector window, which is formed by etching a portion of the insulating layer between the first metal thin film electrodes and exposing the planar silicon, passivation layer provided on the detector window and single layer of fluorinated graphene, which is coated on the passivation layer, where two ends of the fluorinated graphene form an ohmic contact with the first metal thin film electrode respectively, such that attaining construction of photoconductive type photodetector, second metal thin film electrode is coated on back side of the planar silicon and fluorinated graphene forms heterojunction with the planar silicon, such that attaining construction of silicon/fluorinated graphene photodiode type photodetector, the photodetector operates in photoconductive mode, when the first metal thin film electrodes are utilized as working electrodes and the photodetector operates in photodiode mode, when any one of the metal thin film electrode and the second metal thin film electrode are utilized as working electrode. An INDEPENDENT CLAIM is also included for a method for preparing the dual-mode broadband photodetector.