We unify two prevailing theories of thermal quenching (TQ) in rare-earth-activated inorganic phosphors -the cross-over and auto-ionization mechanisms -into a single predictive model. Crucially, we have developed computable descriptors for activator environment stability from ab initio molecular dynamics simulations to predict TQ under the cross-over mechanism, which can be augmented by a band gap calculation to account for auto-ionization. The resulting TQ model predicts the experimental TQ in 29 known phosphors to within ~ 10-11%. Finally, we have developed an efficient topological approach to rapidly screen vast chemical spaces for the discovery of novel, thermally robust phosphors.

The development of extra-broadband phosphors is essential for next-generation illumination with better color experience. In this work, we report the discovery of the first-known Eu2+-activated full-visible-spectrum phosphor, Sr2AlSi2O6N:Eu2+, identified by combining data mining of high-throughput density functional theory calculations and experimental characterization. Excited by UV-light-emitting diodes (LEDs), Sr2AlSi2O6N:Eu2+ shows a superbroad emission with a bandwidth of 230 nm, the broadest emission bandwidth ever reported, and has excellent thermal quenching resistance (88% intensity at 150 °C). A prototype white LED utilizing only this full-visible-spectrum phosphor exhibits superior color quality (R a = 97, R 9 = 91), outperforming commercial tricolor phosphor-converted LEDs. These findings not only show great promise of Sr2AlSi2O6N:Eu2+ as a single white emitter but also open up in silico design of full-visible-spectra phosphor in a single-phase material to address the reabsorption energy loss in commercial tricolor phosphor mixture.

The luminescence of rare earth ions (Eu 2+ , Ce 3+ , and Eu 3+ )-doped inorganic solids is attractive for the screening of phosphors applied in solid-state lighting and displays and significant to probe the occupied crystallographic sites in the lattice also offering new routes to photoluminescence tuning. Here, we report on the discovery of the Eu-and Ce-activated K 3 YSi 2 O 7 phosphors. K 3 YSi 2 O 7 :Eu is effectively excited by 450 nm InGaN blue light-emitting diodes (LEDs) and displays an orange-red emission originated from characteristic transitions of both Eu 2+ and Eu 3+ , while K 3 YSi 2 O 7 :Ce 3+ shows green emission upon 394 nm nearultraviolet (NUV) light excitation. Rietveld refinement verifies the successful doping of the activators, and density functional theory (DFT) calculations further support that Eu 2+ occupies both K1 and Y2 crystallographic sites, while Ce 3+ and Eu 3+ only occupy the Y2 site; hence, the broad-band red emission of Eu 2+ are attributed to a small DFT band gap (3.69 eV) of K 3 YSi 2 O 7 host and a selective occupancy of Eu 2+ in a highly distorted K1 site and a high crystal field splitting around Y2 sites. The white LEDs device utilizing orange-red-emitting K 3 YSi 2 O 7 :Eu and green-emitting K 3 YSi 2 O 7 :Ce 3+ exhibits an excellent CRI of 90.1 at a correlated color temperature of 4523 K. Our work aims at bridging multivalent Eu 2+ /Eu 3+ and Ce 3+ site occupancy in the same host to realize photoluminescence tuning and especially exposes new ways to explore new phosphors with multicolor emission pumped by blue and NUV light for white LEDs.

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Computers, televisions, and smartphones are revolutionized by the invention of InGaN blue light‐emitting diode (LED) backlighting. Yet, continual exposure to the intense blue LED emission from these modern displays can cause insomnia and mood disorders. Developing “human‐centric” backlighting that uses a violet‐emitting LED chip and a trichromatic phosphor mixture to generate color images is one approach that addresses this problem. The challenge is finding a blue‐emitting phosphor that possesses a sufficiently small Stokes’ shift to efficiently down‐convert violet LED light and produce a narrow blue emission. This work reports a new oxynitride phosphor that meets this demand. K3AlP3O9N:Eu2+ exhibits an unexpectedly narrow (45 nm, 2206 cm−1), thermally robust, and efficient blue photoluminescence upon violet excitation. Computational modeling and temperature‐dependent optical property measurements reveal that the narrow emission arises from a rare combination of preferential excitation and site‐selective quenching. The resulting chromaticity coordinates of K3AlP3O9N:Eu2+ lie closer to the vertex of the Rec. 2020 than a blue LED chip and provides access to ≈10% more colors than a commercial tablet when combined with commercial red‐ and green‐emitting phosphors. Alongside the wide gamut, tuning the emission from the violet LED and phosphor blend can reduce blue light emissions to produce next‐generation, human‐centric displays.