An ultra-strong non-pre-irradiation and self-recoverable mechanoluminescent elastomer

Mechanoluminescence (ML) is the luminescence responses to mechanical stimuli and offers a variety of significant applications in lighting, anticounterfeiting, sensors and imaging. At present, the only efficient ML materials are sulphides and trap-controlled oxides. In this paper, we report the ultra-strong green ML of a new Lu3Al5O12: Ce3+-based elastomer that is much stronger than previously reported ML elastomers. Significantly, the ML of this elastomer does not require any pre-irradiation and can be stably stimulated thousands of times due to the unique feature of self-recoverability. It reveals that the ML of this elastomer is irrelevant to the trap levels of materials and the piezoelectricity of structures. Accordingly, a possible ML mechanism is proposed. The Lu3Al5O12: Ce3+-based elastomer can be considered a third type of ML material in addition to the well-known sulphides and trap-dependent oxides. Accordingly, a schematic diagram of the characteristic fields for the present ML materials is depicted. Our results are pioneering in ML fields and may guide future investigations on ML, thereby promoting further utilization of ML.