1：Experimental Design and Method Selection:

The study employed pulsed laser deposition (PLD) to synthesize BexCdyZn1?x?yO quaternary alloy films on c-plane sapphire substrates. The optical bandgap was tuned by adjusting the O2 pressure during growth.

2：Sample Selection and Data Sources:

The films were characterized using XRD, XRR, FE-SEM, AFM, UV-visible-near-infrared spectrophotometry, energy-dispersive spectroscopy, and XPS.

3：List of Experimental Equipment and Materials:

A KrF excimer laser (Lambda Physik COMPEX PRO 205 F, λ = 248 nm) was used for ablation. The films were analyzed using a four-circle single-crystal x-ray diffractometer (XRD; Bruker, D8 discover), field-emission scanning electron microscope (FE-SEM; JSM7100F, JEOL), atomic force microscopy (AFM; NT-MDT, Solver Nano), and UV-visible-near-infrared spectrophotometry (UV 3600 plus, Shimadzu).

4：Experimental Procedures and Operational Workflow:

The films were deposited at various O2 pressures (0–6 Pa) with the substrate temperature maintained at 750°C. The photodetectors were fabricated by patterning Al parallel electrodes on the film surface.

5：Data Analysis Methods:

The optical bandgap was determined using Tauc’s relation for direct-band-gap semiconductors. The photoresponsivity and detectivity were calculated based on the photocurrent and dark current measurements.