1：Experimental Design and Method Selection:

Thin films of In4Se3 and Sn doped In4Se3 are prepared by reactive evaporation, a variant of Günther's three temperature method. High purity indium, selenium, and tin are evaporated simultaneously from resistively heated sources under a vacuum of 10?5 mbar onto glass substrates kept at 548 ± 5 K. The deposition rates are optimized, and Sn doping is achieved by controlled evaporation with Sn mass at 5 wt% and 10 wt% of In for different samples.

2：Sample Selection and Data Sources:

Three samples are prepared: Sample A (undoped In4Se3), Sample B (Sn doped with 5 wt% Sn), and Sample C (Sn doped with 10 wt% Sn). Samples are characterized using various techniques.

3：List of Experimental Equipment and Materials:

Equipment includes Bruker AXS D8 advance X-ray diffractometer (XRD), Kratos Analytical AMICUS X-ray photoelectron spectrometer (XPS), Carl Zeiss Sigma Field Emission Scanning Electron Microscope (FESEM), JASCO V 570 UV-Vis-NIR spectrophotometer, APLAB 1015 digital multimeter, quartz halogen tungsten filament lamp (12 V, 100 W), conductivity cell, Veeco Dektak 6 M Stylus Profiler, and Ecopia HMS-3000 Hall measurement system. Materials include high purity indium (99.999%), selenium (99.99%), tin (99.999%), and glass substrates.

4：999%), selenium (99%), tin (999%), and glass substrates. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Deposition is performed under vacuum with controlled evaporation rates. Characterization involves XRD for structural analysis (2θ range 5°–60°), XPS for composition and oxidation states, FESEM for surface morphology, UV-Vis-NIR for optical transmission, Hall measurements for electrical properties, photoconductivity measurements with light illumination, and temperature-dependent conductivity studies.

5：Data Analysis Methods:

XRD data are analyzed using d-value comparison with standard JCPDS data, texture coefficient calculation, and Williamson-Hall plot for crystallite size and microstrain. XPS data are used for elemental composition and binding energy analysis. Optical data are analyzed using Tauc's relation for band gap determination and Swanepoel's method for refractive index. Electrical data are analyzed using Hall measurements and Arrhenius plots for activation energy. Photoconductivity data are analyzed for decay time constant, photosensitivity, and photoresponsivity.