Guangyin Qu,Xiaojuan Zhang,Siqi Li,Yan Kuai,Feng Xu,Liang Lu,Yu Liu,Zhigang Cao,Benli Yu,Anderson S. L. Gomes,Zhijia Hu
In contrast to conventional anti-counterfeiting technologies, which are susceptible to decryption and exhibit limited effectiveness, the utilization of light to dynamically configure soft materials in a fully reversible and programmable manner not only enhances data security but also improves anti-counterfeiting performance. However, achieving precise control over reflection structural colors and laser wavelengths within a broad dynamic range remains a challenge. In this study, a UV-responsive soft helical superstructure is established by combining a photochromic compound with chiral liquid crystals (LCs). By manipulating the Bragg reflection angle, structural reflection colors ranging from red to cyan are successfully achieved. The introduction of an anti-counterfeiting technique that embeds diverse micro-structures provides features such as color adjustability, erasability, and angle-dependent stability. Using the unique properties of this soft helical superstructure, the implementation of a wavelength-tunable LC bandgap laser through optically reconfigurable Förster resonance energy transfer processes is showcased. Furthermore, a straightforward prototype information encoder is developed to mimic the processes of information encoding and decoding, bypassing the need for complex algorithm design. This research underscores the practicality of LC helical soft systems, emphasizing their distinctive responsiveness to light and their applicability in optical programming photonics.
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 (Na 0.5 Bi 0.5 ) 0.96 Er 0.04 Bi 2 Nb 2 O 9.02 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 (Na 0.5 Bi 0.5 ) 0.96 Er 0.04 Bi 2 Nb 2 O 9.02 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 ( 2 H 11/2 / 4 S 3/2 and 4 S 3/2 / 4 F 9/2 ) as well as the lifetime of the 4 S 3/2 excited state of the Er 3+ 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.
危险品化学品经营许可证（带存储）