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.