Figure 1.

XRD patterns of a) the composite target and b) the Li₃OCl film deposited using the composite target. Strong peaks of Li₂O and LiCl with only a very weak peak of Li₃OCl (110) (star mark) indicate that the composite target is mainly a mixture of raw materials of Li₂O and LiCl. In the as‐deposited film, sharp peaks of the cubic Li₃OCl perovskite can be observed without any peak from Li₂O or LiCl. The symbols of ♥, ♦, and ● indicate the peaks of the ZnO protective layer, Cu sample holder, and stainless steel substrate, respectively.