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

Red‐emitting piezoluminescence (elasticoluminescence) is achieved by doping rare earth Pr3+ into the well‐known piezoelectric matrix, LiNbO3. By precisely tuning the Li/Nb ratio in nonstoichiometric Li x NbO3:Pr3+, a material that exhibits an unusually high piezoluminescence intensity, which far exceeds that of any well‐known piezoelectric material, is produced. Li x NbO3:Pr3+ 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. Red‐emitting piezoluminescence is achieved by doping rare earth Pr3+ into the well‐known piezoelectric matrix, LiNbO3, which shows excellent strain sensitivity at the lowest strain level, with no threshold for stress sensing. This significant finding will greatly improve the dynamic scale and accuracy of mechanoluminescence detection, and is particularly beneficial to the development of bio‐imaging with single‐cell resolution.