Deep red BaTiF₄:Mn⁴⁺ phosphor: synthesis, optical properties and application for warm WLED devices

Non-rare-earth based red phosphor discovery is of great interest in the field of energy-efficient WLED lighting. In this work, we give the hydrothermal synthesis of BaTiF₄:Mn⁴⁺ phosphor. The phase and microstructure of the obtained BaTiF₄:Mn⁴⁺ phosphors have been investigated with the aids of X-ray diffraction spectroscopy and scanning electronic microscope. Under the excitation of blue light, BaTiF₄:Mn⁴⁺ phosphors exhibit red emission originating from the \(^{2}{{E}_{g}}{{\to }^{4}}{{A}_{2g}}\) transitions of Mn⁴⁺ ions. Simultaneously, the concentration and thermal quenching also have been investigated systematically, and the quenching mechanism has been elucidated in detail. Employing BaTiF₆:Mn⁴⁺ as red phosphor, we fabricate a high-performance WLED with a low correlated color temperature of 3857 K and a high color rendering index of 85.3. Based on the improvement of correlated color temperature and color rendering index, the BaTiF₆:Mn⁴⁺ red phosphors supplement the deficiency of WLEDs fabricated by combining blue chip and only YAG:Ce³⁺, which suggest that it is a promising commercial red phosphor in warm WLEDs.