Pulsed laser deposited BexZn1-xO1-ySy quaternary alloy films: structure, composition, and band gap bowing

•We grew quaternary BeZnOS films by PLD with self-made Be0.06Zn0.94O0.27S0.73 target and O2.•Single-phase BeZnOS films were grown successfully on c-sapphire for the first time.•Lattice parameter c and Eg of single-phase BeZnOS alloys were determined.•The optical bandgap shows a bowing behavior, and can be adjusted between 3.55 and 3.10eV.•BeZnOS exhibits enhanced solid solubility of S (y≤0.17 or y≥0.35) compared to ZnOS.