Solubility limits and phase structures in epitaxial ZnOS alloy films grown by pulsed laser deposition

► High-quality epitaxial ZnOS films were grown by PLD using a ZnS ceramic target and O2 as reactive gas. ► Single-phase ZnO1−xSx (0 ⩽ x ⩽ 0.23 and 0.94 ⩽ x ⩽ 1) alloys with a wurtzite structure were achieved. ► Phase separation was observed in ZnO1−xSx films of 0.23 < x < 0.94. ► The S solubility is extended to 0.23 while the O solubility of 0.06 is additionally given. ► Ablating the ZnS while oxidizing is an efficient way towards ZnOS alloys formation.