1：Experimental Design and Method Selection

The study utilized exfoliated SnSe2 nanosheets for photodetector fabrication, focusing on extending the detection range to THz frequencies. The methodology included the use of field-effect transistor (FET) configurations and the exploitation of hot-electron effects under deep-subwavelength electromagnetic focus.

2：Sample Selection and Data Sources

Single crystals of SnSe2 were prepared by the Bridgman method, and nanosheets were mechanically exfoliated from these crystals for device fabrication.

3：List of Experimental Equipment and Materials

Equipment included an atomic force microscope (AFM) for thickness measurement, Raman spectroscopy for material characterization, X-ray diffraction (XRD) for crystal structure analysis, and electron beam lithography (EBL) for device patterning. Materials included SnSe2 nanosheets, Cr/Au for electrodes, and a highly doped silicon substrate as a backgate.

4：Experimental Procedures and Operational Workflow

The fabrication process involved defining source/drain patterns using EBL, depositing Au/Cr film for electrodes, and lift-off to create contact terminals. Photoelectric measurements were performed at room temperature under various wavelengths.

5：Data Analysis Methods

Photocurrent and responsivity were measured as functions of incident power and bias voltage. The performance was evaluated based on responsivity, response time, and noise equivalent power (NEP).