“…[4][5][6] PLNPs constitute hosts, emission centers, and traps. 7 The hosts, such as aluminates, silicates, galliates, sulfides, fluorides, and germanates, 8 are the matrices to integrate the emission center and trap. 9 After the emission centers, including lanthanide, transition, and some main group elemental metal ions, 10 are introduced, the optical properties of the host were obviously improved for PLNPs, especially the near-infrared (NIR) emission.…”