1：Experimental Design and Method Selection:

The study involved annealing PbSe thin films under oxygen atmosphere to sensitize them, followed by characterization using CAFM for surface current and morphology mapping, XPS for chemical state analysis, and fabrication of photoconductive devices with interdigital Au electrodes. Performance was measured using a collimated black-body source.

2：Sample Selection and Data Sources:

Polycrystalline PbSe thin films deposited on intrinsic (100)-oriented Si substrates via physical vapor deposition (PVD) were used. Samples included as-deposited and annealed (sensitized) films.

3：List of Experimental Equipment and Materials:

Equipment includes CAFM (Conductive Atomic Force Microscope), XPS (X-ray Photoelectron Spectroscopy), and a collimated black-body set. Materials include PbSe thin films, Si substrates, PtIr coated Si tips, and Au electrodes.

4：Experimental Procedures and Operational Workflow:

Films were annealed at 300°C under oxygen atmosphere near atmospheric pressure. CAFM was used with a fixed bias of 5V between PtIr coated Si tips and sample to map surface current and morphology. XPS identified chemical states of Pb and Se. Photoconductive devices were fabricated by depositing interdigital Au electrodes, and performance was measured at room temperature with infrared radiation from a black-body set at 500K.

5：0K. Data Analysis Methods:

5. Data Analysis Methods: Data analysis involved comparing XPS spectra for chemical state changes, CAFM images for current distribution and roughness (RMS), and evaluating photoconductive performance using the increment ratio of current under illumination.