Mechanoluminescent Phosphors

Abstract

Mechanoluminescent (ML) phosphors are a group of smart materials able to sense mechanical actions and convert part of the mechanical energy into photon emission. In the last two decades, emission-reproducible ML phosphors represented by SrAl2O4:Eu2+ and ZnS:Cu/Mn2+ have attracted extensive attention and exhibited great prospects in advanced sensing technologies. Some ML phosphors have entered into practical applications. However, the development of ML phosphors and ML-based sensing technologies is still on the rise with many problems and is still unsolved. Specifically, the relationship between the crystal structure/microstructure of ML phosphors and the ML property is still unclear; the mechanism of ML is controversial; a standardized instrument for the characterization of ML phosphors and ML-based stress sensors is lacking; the performances of existing ML phosphors still cannot well meet the requirements of advanced sensing technology. It is believed that the next few years will witness the rapid development of ML fluorescent materials and ML-based sensing technologies.