Realization of blue-white light emission in Zn2+-doped CsCdCl3 metal halides

In recent years, metal halides have attracted much attention because of their fascinating optical properties . However, realizing an emission with efficient white light afterglow is still a great challenge. Here, high-purity Zn 2+ -doped CsCdCl 3 crystals have been synthesized by a hydrothermal method . Part of the Zn 2+ ions replace part of the Cd 2+ ions in the coplanar octahedron , so atomically confined excitons are formed around the coplanar octahedron . This exciton produces blue emission with a center wavelength of 422 nm at room temperature , but also produces weak STE at 595 nm. This is due to the dominance of confined exciton ( Cd CE) luminescence and suppression of intrinsic STE with PLQY reaching 44.53 %. Doping of Zn 2+ emits a white afterglow at room temperature. Raman and pyroelectric spectroscopic analyses show that the A 1g 246 cm −1 phonon mode plays an important role in the electron-phonon coupling process and dominates the afterglow luminescence process. In addition, white light emitting diodes (WLEDs) were fabricated with Zn 2+ doped CsCdCl 3 to show their potential in lighting applications. • Formation of atomically confined excitons in CsCdCl 3 :Zn 2+ crystals produces blue emission at 422 nm and also weak STE at 595 nm. • CsCdCl 3 : Zn 2+ crystals have white light afterglow properties and its PLQY reaches 44.53 %. • A 1g 246 cm −1 phonon mode plays an important role in electron-phonon coupling and controls the afterglow luminescence process.