During the downconversion process, a high-energy photon is converted into multiple low-energy photons, which results in a high luminous efficiency in both photoluminescent and electroluminescent devices. This phenomenon has been applied in various fields, including solar cells, plasma display panels (PDP), and green lighting technologies such as mercury-free fluorescent lamps. However, the concept of downconversion (quantum cutting) has not been fully explored in the context of mechanoluminescent materials. In this study, we successfully synthesized a heterojunction of CaF2/CaZnOS exhibiting efficient downconversion mechanoluminescence (ML) properties. By controlling the CaF2 to CaZnOS ratio and incorporating Tb3+ doping, we obtained a highly effective heterojunction structure that significantly enhanced ML. Moreover, we extended this material to several commonly utilized downconversion ion …