Alkaline-Earth-Metal-Ions Blending Enhanced Self-Activated and Bi3+-Activated Mechanoluminescence from Ca1-xBaxZnOS

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 Ca 2+ of CaZnOS with Ba 2+ and vice versa, intense and eye-visible ML is achieved via exerting a small mechanical stimulus of 2 N onto the obtained Ca 1-x Ba x ZnOS (0 < x < 1). The luminescence center for ML of Ca 1-x Ba x ZnOS is intrinsic oxygen vacancy, so that Ca 1-x Ba x ZnOS can give off efficient and self-activated ML. Under optimum conditions, the maximum ML emission of Ca 0.84 Ba 0.16 ZnOS is about 50-folds and 170-folds to that of CaZnOS and BaZnOS, respectively. Promisingly, Bi 3+ can be incorporated into the lattice of Ca 1-x Ba x ZnOS, transferring ML center from the oxygen defects of Ca 1-x Ba x ZnOS to the activator of Ca 0.96-x Ba x ZnOS:Bi 0.04 , and eventually enable further enhanced ML by about twofolds. This alkaline-earth-metal-ion blending strategy can also enhance Bi 3+ -activated ML from M 0.96 ZnOS:Bi 0.04 , the maximum emission for ML of Ca 0.80 Ba 0.16 ZnOS:Bi 0.04 is 36-folds and 38 folds to that of Ca 0.96 ZnOS:Bi 0.04 and Ba 0.96 ZnOS:Bi 0.04 , respectively. This work opens an avenue to develop new ML hosts and luminophores with efficient emission.