Alkaline‐Earth‐Metal‐Ions Blending Enhanced Self‐Activated and Bi³⁺‐Activated Mechanoluminescence from Ca_1‐xBa_xZnOS

Abstract The self‐activated mechanoluminescence (ML) of oxysulfides MZnOS (M = Ca, Sr, Ba) is very weak, and bright ML from these hosts is usually achieved with activator‐doping strategy. Herein, a promising alkaline‐earth‐metal‐ion blending strategy, instead of activator doping, is proposed to achieve intense and self‐activated ML from MZnOS. Upon partially substituting the Ca²⁺ of CaZnOS with Ba²⁺ and vice versa, intense and eye‐visible ML is achieved via exerting a small mechanical stimulus of 2 N onto the obtained Ca_1‐xBa_xZnOS (0 < x < 1). The luminescence center for ML of Ca_1‐xBa_xZnOS is intrinsic oxygen vacancy, so that Ca_1‐xBa_xZnOS can give off efficient and self‐activated ML. Under optimum conditions, the maximum ML emission of Ca_0.84Ba_0.16ZnOS is about 50‐folds and 170‐folds to that of CaZnOS and BaZnOS, respectively. Promisingly, Bi³⁺ can be incorporated into the lattice of Ca_1‐xBa_xZnOS, transferring ML center from the oxygen defects of Ca_1‐xBa_xZnOS to the activator of Ca_0.96‐xBa_xZnOS:Bi_0.04, and eventually enable further enhanced ML by about twofolds. This alkaline‐earth‐metal‐ion blending strategy can also enhance Bi³⁺‐activated ML from M_0.96ZnOS:Bi_0.04, the maximum emission for ML of Ca_0.80Ba_0.16ZnOS:Bi_0.04 is 36‐folds and 38 folds to that of Ca_0.96ZnOS:Bi_0.04 and Ba_0.96ZnOS:Bi_0.04, respectively. This work opens an avenue to develop new ML hosts and luminophores with efficient emission.