Reproducible mechanical-to-optical energy conversion in Mn (II) doped sphalerite ZnS

Mechanoluminescenece (ML) is a dynamic luminescence phenomenon of materials under various mechanical stimulation. Impurity doped ZnS shows high ML repeatability without any needs for extra excitation sources, thus making it very promising in applications like stress sensing and battery-free new light source. Lots of progress has been made in the last decades, however, the reproducible ML (RML) mechanism is still unclear to explain some basic phenomena like how the electron is excited to conduction band when undergoing mechanical actions or how the excitation energy is transferred to the dopants so efficiently. Based on comparative study of photoluminescence (PL) and ML in Mn2+ doped ZnS prepared via melt-salt method, the RML energy routes in sphalerite ZnS: Mn2+ is proposed herein, and further, a general mechanism is supposed which could apply to other RML systems. The excitation of RML is possibly generated by electron transfer during bond rebuilding in plastic deformation while the highly efficient energy transfer is realized through hole and electron capture by the dopant. According to this mechanism, we provide some prospects for further optimization of RML performance as well as discovery of new RML materials.

Automated summary

Mechanoluminescence (ML) is a dynamic luminescence phenomenon of materials under various mechanical stimulation. The reproducible ML (RML) mechanism is still unclear, possibly generated by electron transfer and highly efficient energy transfer in ZnS: Mn2+ systems.