Strongly confined ligand-free, defect-free, hydroxy terminated ZnO quantum dots with a mean diameter of 1.9 nm were synthesized by radio frequency atmospheric pressure microplasma. Photoluminescence studies show strong confinement effect on emission with only ultraviolet (UV) emission without any defect-related visible emission. The mechanism responsible for this UV emission is also discussed and originates from OH-related surface terminations (Nanotechnology 31, 2020, 215707).