Learning from a Mineral Structure toward an Ultra‐Narrow‐Band Blue‐Emitting Silicate Phosphor RbNa₃(Li₃SiO₄)₄:Eu²⁺

Abstract

Learning from natural mineral structures is an efficient way to develop potential host lattices for applications in phosphor converted (pc)LEDs. A narrow-band blue-emitting silicate phosphor, RbNa (Li SiO ) :Eu (RNLSO:Eu ), was derived from the UCr C -type mineral model. The broad excitation spectrum (320-440 nm) indicates this phosphor can be well matched with the near ultraviolet (n-UV) LED chip. Owing to the UCr C -type highly condensed and rigid framework, RNLSO:Eu exhibits an extremely small Stokes shift and an unprecedented ultra-narrow (full-width at half-maximum, FWHM=22.4 nm) blue emission band (λ =471 nm) as well as excellent thermal stability (96 %@150 °C of the initial integrated intensity at 25 °C). The color gamut of the as-fabricated (pc)LEDs is 75 % NTSC for the application in liquid crystal displays from the prototype design of an n-UV LED chip and the narrow-band RNLSO:Eu (blue), β-SiAlON:Eu (green), and K SiF :Mn (red) components as RGB emitters.

Trap distribution and photo‐stimulated luminescence in LaSrAl3O7:Eu2+ long‐lasting phosphors for optical data storage

“…XRD Rietveld refinement offers the method to confirm the real structure of the prepared sample, as present in Figure A. The results show that the XRD peaks are in good agreement with the starting model of LaSrAl 3 O 7 (ICSD 109439), and the indictor of goodness of weight profile factor R wp is 7.68% . The final refined results determine that the sample belongs to tetragonal crystalline structure LSA with space group of P42 1 m and the unit cell parameters are a = b = 7.921 Å, c = 5.343 Å.…”

Novel cyan‐emitting KBaScSi2O7:Eu2+ phosphors with ultrahigh quantum efficiency and excellent thermal stability for WLEDs

“…The room temperature PLE and PL spectra of KBSS: Eu 2+ phosphor is displayed in Figure . The PLE spectrum indicates a broad band in the range of 290‐450 nm ascribed to the electronic transition from the ground state 4 f 7 to excited state 4 f 6 5 d 1 of Eu 2+ ions . Clearly, the PLE spectrum covers the UV region, demonstrating that KBSS: Eu 2+ phosphor can be used in NUV/UV‐pumped LED.…”

“…Among a large number of possible matrices, silicate compound system is deemed to be applicable candidates as the luminescence matrix because of their excellent chemical, physical, and thermal stability, relatively easy preparation as well as their abundance in nature . As a result, many Eu 2+ ‐doped silicate‐based blue‐ and green‐emitting phosphor have been investigated, for instance the commercial (Sr,Ba) 2 SiO 4 :Eu 2+ , RbNa(Li 3 SiO 4 ) 2 :Eu 2+ , K 2 Ba 7 Si 16 O 40 :Eu 2+ , KBaYSi 2 O 7 :Eu 2+ , RbBaScSi 3 O 9 :Eu 2+ , etc. Among them, the Sc silicates have special three dimensional framework structures comprising of abundant tetrahedra and octahedra, which provide adequate crystal chemistry environment for various active ions .…”

Ca2Na2La6(SiO4)4(PO4)2O: Eu2+/Eu3+: A visual dual‐emitting fluorescent ratiometric temperature sensor

“…As two different states of a same rare earth element, Eu 2+ and Eu 3+ show noticeably different luminescent properties due to their different electronic structures. Compared with the red emission from the f‐f transition of Eu 3+ , the degree of splitting in the 5d energy level of Eu 2+ is determined by the strength of the crystal field and can produce various colors in different luminescence hosts . Moreover, based on the diversity of their electronic structure, Eu 3+ usually has a higher activation energy and shows a slighter thermal quenching than Eu 2+ .…”