Facile Synthesis of Highly Emissive All-Inorganic Manganese Bromide Compounds with Perovskite-Related Structures for White LEDs

• Published in: Molecules (Basel, Switzerland) Switzerland), 2022-11, Vol.27 (23), p.8259
• Main Authors: Gao, Ping, Cheng, Suwen, Liu, Jiaxin, Li, Junjie, Guo, Yanyan, Deng, Zhengtao, Qin, Tianshi, Wang, Aifei
• Format: Article
• Language: English
• Subjects: Bromides; Calcium Compounds; Color; Color temperature; Cs3MnBr5; Diffraction; Emission spectra; Fluorescence; Inorganic Chemicals; Lead free; Light emitting diodes; Manganese; manganese halide; Optical properties; Oxides; Perovskite; Perovskites; Phase transitions; phosphor; Photoluminescence; Photons; Ratios; Visible spectrum; white LEDs; White light
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules27238259

Lead-free all-inorganic halide materials with different Mn -based crystal structures (Cs MnBr and CsMnBr ) were obtained using a convenient synthetic method. Cs MnBr had a bright green emission (522 nm), with a unique single-exponential lifetime (τ = 236 µs) and a high photoluminescence quantum yield (82 ± 5%). A red emission was observed in the case of the CsMnBr structure with a two-exponential fluorescence decay curve, and the lifetime was 1.418 µs (93%) and 18.328 µs (7%), respectively. By a judicious tuning of the synthetic conditions, a mixed phase of Cs MnBr /CsMnBr was also produced that emitted white light, covering almost the entire visible spectrum. White-light-emitting diodes (WLEDs) with color coordinates (0.4269, 0.4955), a color temperature of (3773 K), and a color rendering index (68) were then fabricated using the as-prepared powder of mixed phases of Cs MnBr /CsMnBr with a commercial UV LED chip (365 nm).