LiNbO3:Pr3+: A Multipiezo Material with Simultaneous Piezoelectricity and Sensitive Piezoluminescence

Red‐emitting piezoluminescence (elasticoluminescence) is achieved by doping rare earth Pr 3+ into the well‐known piezoelectric matrix, LiNbO 3 . By precisely tuning the Li/Nb ratio in nonstoichiometric Li x NbO 3 :Pr 3+ , a material that exhibits an unusually high piezoluminescence intensity, which far exceeds that of any well‐known piezoelectric material, is produced. Li x NbO 3 :Pr 3+ shows excellent strain sensitivity at the lowest strain level, with no threshold for stress sensing. These multipiezo properties of sensitive piezoluminescence in a piezoelectric matrix are ideal for microstress sensing, damage diagnosis, electro‐mechano‐optical energy conversion, and multifunctional control in optoelectronics.