Mechanoluminescent properties of europium complexes

Mechanoluminescence (ML) from polymer-dispersed films of europium complexes was investigated for the first time. We synthesized four new kinds of europium complexes and examined their mechanoluminescent properties in different sample forms: powder and polymer-dispersed film. While only two complexes exhibited ML in powder form, all the four became mechanoluminescent when dispersed in polymer matrix. The excitation mechanism of ML of the complexes is studied by the measurement of the spectral and transient behavior.