1：Experimental Design and Method Selection:

The study adopted pulsed laser deposition (PLD) to grow BaSi2 thin films on transparent SiO2 and CaF2 substrates. The crystalline quality, optical and photoresponse properties were investigated.

2：Sample Selection and Data Sources:

SiO2 and CaF2(111) substrates were used. A thin Si buffer layer was introduced on SiO2 substrate for some samples to improve crystalline quality.

3：List of Experimental Equipment and Materials:

PLD system (Seinan Industries PLD200) equipped with a 248-nm krypton fluoride excimer laser (Coherent CompexPro), stylus profiler (Bruker Dektak XT), energy dispersive spectrometer (EDS).

4：Experimental Procedures and Operational Workflow:

Substrates were cleaned and loaded into the PLD chamber. BaSi2 thin films were deposited at various growth temperatures. The thicknesses and Ba/Si ratios of the films were measured.

5：Data Analysis Methods:

X-ray diffraction and Raman spectroscopy were used to analyze the crystalline quality. Absorption spectra and photoresponse spectra were measured to evaluate optical and photoelectric properties.