Upconverted luminescence from lanthanide-doped ferroelectrics for optical storage and triple-mode temperature probing

Developing smart luminescent materials with desirable and tunable characteristics has always been an overriding priority of fluorescence technology. However, huge challenges encompass the single functionality of the luminescent materials and the traditional chemical synthetic techniques with rigorously controlling over the miscellaneous experimental conditions and variables. Herein, the lanthanide-doped bismuth-layered ferroelectric (Na0.5Bi0.5)0.96Er0.04Bi2Nb2O9.02 has been prepared to be utilized as a platform that not only serves the in-situ and reversible tailoring of the upconverted emission via physical methods, but also enable the versatile functionalities such as photomemory and multi-modal temperature sensing. High luminescent contrast that can reach up to 83.7 % before and after the 405 nm irradiation has been realized on the basis of the photochromic phenomenon of the as-prepared(Na0.5Bi0.5)0.96Er0.04Bi2Nb2O9.02 sample, and the fundamental application in the photomemory has been exhibited. Moreover, the performances of triple-mode thermometry built on the fluorescent intensity ratio techniques (2H11/2/4S3/2 and 4S3/2/4F9/2) as well as the lifetime of the 4S3/2 excited state of the Er3+ ion have been investigated in carefulness, with the maximal relative sensitivities of 1.22 % K-1 at 300 K, 0.92 % K-1 at 510 K, and 0.18 % K-1 at 450 K, respectively. Our results provide significant insights into the methodology of physically modulating the upconversion luminescence, and offer a glamorous pathway for multifunctional high-end applications.