Ferroelectric Sr3Sn2O7:Nd3+: A New Multipiezo Material with Ultrasensitive and Sustainable Near‐Infrared Piezoluminescence

Abstract Ultrasensitive and sustainable near‐infrared (NIR)‐emitting piezoluminescence is observed from noncentrosymmetric and ferroelectric‐phase Sr 3 Sn 2 O 7 doped with rare earth Nd 3+ ions. Sr 3 Sn 2 O 7 :Nd 3+ (SSN) with polar A2 1 am structure is demonstrated to emit piezoluminescence of wavelength of 800–1500 nm at microstrain levels, which is enhanced by the ferroelectrically polarized charges in the multipiezo material. These discoveries provide new research opportunities to study luminescence properties of multipiezo and piezo‐photonic materials, and to explore their potential as novel ultrasensitive probes for deep‐imaging of stress distributions in diverse materials and structures including artificial bone and other implanted structures (in vivo, in situ, etc).