Phosphor-converted white light-emitting diodes (pc-WLEDs) are efficient light sources used in lighting, high-tech displays, and electronic devices. One of the most significant challenges of pc-WLEDs is the thermal quenching, in which the phosphor suffers from emission loss with increasing temperature during high-power LED operation. Here, we report a blue-emitting NaSc(PO):xEu phosphor (λ = 453 nm) that does not exhibit thermal quenching even up to 200 °C. This phenomenon of zero thermal quenching originates from the ability of the phosphor to compensate the emission losses and therefore sustain the luminescence with increasing temperature. The findings are explained by polymorphic modification and possible energy transfer from electron-hole pairs at the thermally activated defect levels to the Eu 5d-band with increasing temperature. Our results could initiate the exploration of phosphors with zero thermal quenching for high-power LED applications.

The discovery of new phosphors is key to the development of highly efficient and environmentally friendly LED-based lighting. By applying data-driven structure prediction and quantum mechanics-based screening on unexplored chemistries, we identified a novel, earth-abundant phosphor host, Sr 2 LiAlO 4 , which was successfully synthesized and integrated into prototype LEDs with high color quality.

Organolead halide perovskites have emerged as a promising optoelectronic material for lighting due to its high quantum yield, color-tunable, and narrow emission. Despite their unique properties, toxicity has intensified the search for ecofriendly alternatives through partial or complete replacement of lead. Herein, we report a roomtemperature synthesized Mn 2+ -substituted 3D-organolead perovskite displacing ∼90% of lead, simultaneously retaining its unique excitonic emission, with an additional orange emission of Mn 2+ via energy transfer. A high Mn solubility limit of 90% was attained for the first time in lead halide perovskites, facilitated by the flexible organic cation (CH 3 NH 3 ) + network, preserving the perovskite structure. The emission intensities of the exciton and Mn were influenced by the halide identity that regulates the energy transfer to Mn. Homogeneous emission and electron spin resonance characteristics of Mn 2+ indicate a uniform distribution of Mn. These results suggest that low-toxicity 3D-CH 3 NH 3 Pb 1−x Mn x Br 3−(2x+1) Cl 2x+1 nanocrystals may be exploited as magnetically doped quantum dots with unique optoelectronic properties.

A moisture-stable, red-emitting fluoride phosphor with an organic hydrophobic skin is reported. A simple strategy was employed to form a metal-free, organic, passivating skin using oleic acid (OA) as a hydrophobic encapsulant via solvothermal treatment. Unlike other phosphor coatings that suffer from initial efficiency loss, the OA-passivated KSiF:Mn (KSF-OA) phosphor exhibited the unique property of stable emission efficiency. Control of thickness and a highly transparent passivating layer helped to retain the emission efficiency of the material after encapsulation. A moisture-stable KSF-OA phosphor could be synthesized because of the exceptionally hydrophobic nature of OA and the formation of hydrogen bonds (F···H) resulting from the strong interactions between the fluorine in KSF and hydrogen in OA. The KSF-OA phosphor exhibited excellent moisture stability and maintained 85% of its emission intensity even after 450 h at high temperature (85 °C) and humidity (85%). As a proof-of-concept, this strategy was used for another moisture-sensitive SrSiON:Eu phosphor which showed enhanced moisture stability, retaining 85% of emission intensity after 500 h under the same conditions. White light-emitting devices were fabricated using surface-passivated KSF and YAlO:Ce which exhibited excellent color rendering index of 86, under blue LED excitation.

Catalysis with single-atom catalysts (SACs) exhibits outstanding reactivity and selectivity. However, fabrication of supports for the single atoms with structural versatility remains a challenge to be overcome, for further steps toward catalytic activity augmentation. Here, we demonstrate an effective synthetic approach for a Pt SAC stabilized on a controllable one-dimensional (1D) metal oxide nano-heterostructure support, by trapping the single atoms at heterojunctions of a carbon nitride/SnO2 heterostructure. With the ultrahigh specific surface area (54.29 m2 g–1) of the nanostructure, we obtained maximized catalytic active sites, as well as further catalytic enhancement achieved with the heterojunction between carbon nitride and SnO2. X-ray absorption fine structure analysis and HAADF-STEM analysis reveal a homogeneous atomic dispersion of Pt species between carbon nitride and SnO2 nanograins. This Pt SAC system with the 1D nano-heterostructure support exhibits high sensitivity and selectivity toward detection of formaldehyde gas among state-of-the-art gas sensors. Further ex situ TEM analysis confirms excellent thermal stability and sinter resistance of the heterojunction-immobilized Pt single atoms.