Cs₂MnF₆ Red Phosphor with Ultrahigh Absorption Efficiency

Abstract

To improve absorption efficiency (AE) and subsequently improve external quantum efficiency (EQE) remains one of the significant challenges for Mn4+-doped red-emitting fluoride phosphors. In this study, we propose to use Mn4+ as a part of matrix to enhance the AE of fluoride phosphors. Red-emission phosphors Cs2MnF6, Cs2MnF6:Sc3+, and Cs2MnF6:Si4+ were synthesized successfully by a coprecipitation method. The Rietveld refinement of X-ray diffraction reveals that this red phosphor exhibits a cubic structure in Fm3̅m space group. Owing to Mn4+ being a part of matrix, this kind of red phosphor possesses an extremely high AE, which can be promoted to 88%. The doping of Sc3+ and Si4+ ions into Cs2MnF6 can effectively increase the luminescence intensity to 253 and 232%, respectively, relative to that of Cs2MnF6. The relative emission intensity of Cs2MnF6:5%Si4+ red phosphor preserves about 115% when temperature rises to 175 °C. By employing Cs2MnF6:5%Si4+ as a red-emitting component, high-performance LED-1 with Ra = 86.2, R9 = 82.1 and CCT = 3297 K, and LED-2 with an ultrawide color gamut (NTSC value of 122.3% and rec. 2020 value of 91.3%) are obtained. This work may provide a new idea to explore a new type of fluoride phosphor with high EQE for high-performance white-light-emitting diodes.

Synthesis and luminescence of Cs2HfCl6 micro- and Cs2HfF6 nanoparticles

“…The chemicals used in this procedure are less toxic than the aqueous HF solutions commonly employed for synthesising Cs 2 HfF 6 in the literature. 32,36,37 Moreover, using corrosive HF solutions leads to the formation of microparticles, while the synthesis route reported here yields oleic acid functionalised nanoparticles, as expected for non-aqueous syntheses. Nanoparticle doping is achieved by adding a solution of europium nitrate or manganese acetate in methanol prior to heating the reaction to 160 1C at a concentration of 2.5 mol% with respect to hafnium.…”

Mn4+ non-equivalent doped fluoride phosphors with a short fluorescence decay time for backlighting

“…The thermal quenching stability of phosphors is a significant parameter for their actual utilization in LEDs. 31…”

Combinations of Superior Inorganic Phosphors for Level‐Tunable Information Hiding and Encoding

“…[159] For fluoride phosphors, they are usually synthesized from a mixed solution. [61,160,161] A series of millimeter-sized single-crystal phosphors Cs 2 XF 6 :Mn 4+ (X = Ge, Si, Ti) are prepared by a single-crystals grown up way. The as-prepared phosphors possess bright red emission due to the lower influence of reflection and scattering of single crystalline than that of powders.…”