Efficient and Color‐Tunable Oxyfluoride Solid Solution Phosphors for Solid‐State White Lighting

Abstract

A solid solution strategy helps increase the efficiency of Ce3+ oxyfluoride phosphors for solid‐state white lighting. The use of a phosphor‐capping architecture provides additional light extraction. The accompanying image displays electroluminescence spectra from a 434‐nm InGaN LED phosphor that has been capped with the oxyfluoride phosphor.

Average and Local Structure, Debye Temperature, and Structural Rigidity in Some Oxide Compounds Related to Phosphor Hosts

“…Until recently, a majority of new phosphors were identified through chemical substitution in known compounds, [5][6][7][8] with occasional high throughput searches of familiar parameter space. 9,10 An alternative, potentially more efficient method presented recently employs Density Functional Theory (DFT) to screen for new potential phosphor hosts with high photoluminescent quantum yield (PLQY).…”

KCa4(BO3)3:Ln3+ (Ln = Dy, Eu, Tb) phosphors for near UV excited white–light–emitting diodes

“…28,29 Among all, the oxyfluoride (for example: Sr 2.975-x -Ba x Ce 0.025 AlO 4 F) phosphors have been seen with alacrity as the most efficient matrix for photoluminescence due to their low phonon energy. 19,20 Such low phonon energies are expected to decrease the contribution of non-radiative multi-phonon relaxations during the emission process of dopant rare-earth ions, resulting into enhancement of net emission quantum efficiency. 19,20 However, despite of the high quantum efficiency, fluoride based phosphor systems are very moisture sensitive in nature, thus raising concerns regarding their practical applications.…”

“…19,20 Such low phonon energies are expected to decrease the contribution of non-radiative multi-phonon relaxations during the emission process of dopant rare-earth ions, resulting into enhancement of net emission quantum efficiency. 19,20 However, despite of the high quantum efficiency, fluoride based phosphor systems are very moisture sensitive in nature, thus raising concerns regarding their practical applications. 20 Therefore single-host broad band emitting phosphors need to be developed for low-cost W-LEDs with improved chemical and thermal stability better reproducibility and a simpler fabrication process.…”

“…12,13 However, despite many advantages, the final phosphor product suffers from complexities associated with the combination of several phosphors used in the fabrication and its significant degradation during heating, which reduce the lifetime and efficiency of WLEDs. 10,11,14 The pursuit in this direction has led to identify new class of phosphors having broadband near white emitting properties based on oxides, [15][16][17][18] oxyfluorides, 19,20 nitrides, 21,22 oxynitrides, [23][24][25] sulfides 26,27 and halides. 28,29 Among all, the oxyfluoride (for example: Sr 2.975-x -Ba x Ce 0.025 AlO 4 F) phosphors have been seen with alacrity as the most efficient matrix for photoluminescence due to their low phonon energy.…”

Mesoscale engineering of photonic glass for tunable luminescence

“…7 From the traditional point of view, the structural origin of the spectral broadening is the site-to-site variation of dopants in a specific host matrix. 8,9 The corresponding structural ordering in homogeneous glasses is strictly limited to a short-range order of~5 Å. 10,11 In contrast, the dopant-host matrix and the dopant-dopant interactions are known to operate on a length scale of at least one order of magnitude larger than the short-range order in glass.…”