Cyan-emitting phosphors are important for near-ultraviolet (NUV) light-emitting diodes (LEDs) to gain high-quality white lighting. In the present work, a Bi3+-doped BaScO2F, R+ (R = Na, K, Rb) perovskite, which emits 506 nm cyan-green light under 360 or 415 nm excitation, is obtained via a high-temperature solid-state method for the first time. The obtained perovskite shows improved photoluminescence and thermal stability due to the charge compensation of Na+, K+, and Rb+ co-doping. Its spectral broadening is attributed to two centers Bi (1) and Bi (2), which are caused by the zone-boundary octahedral tilting due to the substitution of Bi3+ for the larger Ba2+. Employing the blend phosphors of Ba0.998ScO2F:0.001Bi3+,0.001K+ and the commercial BAM:Eu2+, YAG:Ce3+, and CaAlSiN3:Eu2+, a full-spectrum white LED device with R a = 96 and CCT = 4434 K was fabricated with a 360 nm NUV chip. Interestingly, a novel strategy is proposed: the cyan-green Ba0.998ScO2F:0.001Bi3+,0.001K+ and orange Sr3SiO5:Eu2+ phosphors were packaged with a 415 nm NUV chip to produce the white LED with R a = 85 and CCT = 4811 K.

The poor water resistance property of a commercial Mn 4+ -activated narrow-band red-emitting fluoride phosphor restricts its promising applications in high-performance white LEDs and wide-gamut displays. Herein, we develop a structural rigidity-enhancing strategy using a novel KHF 2 :Mn 4+ precursor as a Mn source to construct a proton-containing water-resistant phosphor K 2 (H)TiF 6 :Mn 4+ (KHTFM). The parasitic [HMnF 6 ] − complexes in the interstitial site from the fall off the KHF 2 :Mn 4+ are also transferred to the K 2 TiF 6 host by ion exchange to form KHTFM with rigid bonding networks, improving the water resistance and thermostability of the sample. The KHTFM sample retains at least 92% of the original emission value after 180 min of water immersion, while the non-water-resistant K 2 TiF 6 :Mn 4+ (KTFM) phosphor maintains only 23%. Therefore, these findings not only illustrate the effect of protons on fluoride but also provide a novel insight into commercial water-resistant fluoride phosphors.

As a luminous center, Mn2+ has the advantages of high efficiency, safety, and cheap, which has been widely used to improve the color rendering index of garnet structure phosphors. Although,...

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