1：Experimental Design and Method Selection

MZO films were deposited by reactive co-sputtering from elemental Zn and Mg targets in an AJA Orion-5 chamber. The substrate was held stationary during deposition of combinatorial libraries; the substrate was rotated to produce single composition films.

2：Sample Selection and Data Sources

TEC10 glass superstrates were used for devices and were cleaned prior to being loaded into the sputter chamber. Si wafers and glass slides were used for MZO thickness and band gap measurements, respectively.

3：List of Experimental Equipment and Materials

AJA Orion-5 chamber, Zn (99.99%) and Mg (99.95%) targets, TEC10 glass superstrates, Si wafers, glass slides, Micro 90 solution, UV-ozone treatment, isopropanol, Argon and oxygen gases.

4：Experimental Procedures and Operational Workflow

Plasma clean at 50 W for 5 min in 5 mTorr of Ar was performed on all substrates right before MZO deposition. Argon and oxygen were supplied in a 2:1 ratio at P = 5 mTorr. MZO deposition was done without intentional substrate heating.

5：Data Analysis Methods

Kelvin probe was utilized to measure the work function of MZO. Optical transmission measurements for MZO thin films were performed using Cary UV–Vis spectrophotometer. Tauc plots were then constructed based on UV–Vis transmission data to determine the direct band gap of MZO thin films.