Blue Light Hazard Optimization for White Light-Emitting Diode of Mn2+-Activated 0D Cs3Cu2Br5 Perovskite Materials

The zero-dimensional perovskite-like derivative Cs 3 Cu 2 X 5 (X = Cl, Br, I) with self-trapped excitons (STEs) photoluminescence (PL) has attracted tremendous interest in the field of optoelectronics. Nonetheless, it is challenging for Cs 3 Cu 2 Br 5 material to attain full visible spectrum emission and prevent light-induced photochemical damage to the retina (blue light hazard) in applications. Herein, Mn 2+ is chosen as the dopant to alloy into Cs 3 Cu 2 X 5 via a one-step solid state synthesis method. Significantly, the series of Mn 2+ -doped show the emission peak of 460 nm STEs and the emission peak of 550 nm Mn 2+ . More importantly, the high energy absorption of Mn 2+ facilitates the transfer of exciton energy, contributing to a reduction in blue emission peak at 460 nm. Simultaneously, ≈17.5% of Mn 2+ is alloyed into the Cs 3 Cu 2 X 5 lattice to induce the energy transfer channels from the Cs 3 Cu 2 X 5 host to the Mn 2+ guest to lead to the emission of Mn 2+ , which broadens emission spectrum (400–620 nm) and realizes 80% reduction of the blue emission peak at 460 nm. Additionally, a white light-emitting diodes can decrease the blue emission band via 71.45% and an ultrahigh color rendering index (CRI) of 94.5 is produced using the 17.5% Mn 2+ : Cs 3 Cu 2 X 5 perovskite-like derivative powder material.