ABSTRACT Controlling the luminescence behavior of rare‐earth‐doped materials under extreme physical conditions of pressure and/or temperature is crucial for the development of next‐generation solid‐state lighting and optical sensors. Here, the Li 2 SrSiO 4 :3%Eu 2+ ,0.5%Cs + phosphors were synthesized and permanently modified by high‐pressure treatment to design high‐performance white‐LED and optical manometer. With Cs + introduction, the luminescence intensity, quantum efficiency, and thermal stability of the phosphors increased. Using the designed phosphor as a yellow‐emitting component, a white‐LED was fabricated. The studied material was also used to develop a multiparametric optical pressure and temperature sensor. Importantly, compression above 14.0 GPa induced formation of a new high‐pressure β‐phase, which can be recovered under ambient conditions, and ‐ exhibits an unique pressure‐induced emission band. Photoluminescence spectroscopy revealed the presence of yellow and a new blue emission component in the emission spectrum, providing sensitivities of the synthesized phosphors over 9 and 5 nm GPa −1 , respectively. Moreover, the application of high pressure in a large‐format press (up to 20 GPa) enabled the fabrication of a white‐LED device with improved color performance. Such large‐scale, high‐pressure postsynthetic treatment for the development of sensors and new light sources is reported here for the first time.
Woźny et al. (Tue,) studied this question.