A new class of battery-free, mechanically powered, piezoelectric Ca5Ga6O14:Tb3+ phosphors with self-recoverable luminescence

A new class of Ca 5 Ga 6 O 14 :Tb 3+ mechanoluminescent phosphors with trap-independent, self-recoverable mechanoluminescence and a low mechanical stimulus threshold are reported, whose properties originate from piezoelectricity of the host with giant piezoelectric coefficients.