The composition engineering of red‐emitting Eu³⁺‐doped Ca_10.5(PO₄)₇‐type solid solution phosphors and application in LED

Abstract

In this work, using Ca 10.5 (PO 4 ) 7 as the structural model, a number of Eu 3+ -doped [Ca 9 Na 3x Y 1-x (PO 4 ) 7 (CNYP-I, 0 ≤ x ≤ 1/2) ← Ca 10.5 (PO 4 ) 7 → Ca 9+y Na 3/2-y/2 Y (1-y)/2 (PO 4 ) 7 (CNYP-II, 0 ≤ y ≤ 1)] phosphors were designed and synthesized through the heterovalent substitution of Y 3+ and Na + to Ca 2+ . The substitution mechanism, composition structure, luminescence performance, and thermal stability of Eu 3+ -doped CNYP-I (0 ≤ x ≤ 1/2) as well as the solid solutions of CNYP-II (0 ≤ y ≤ 1), were discussed in detail. The morphology and element composition of CNYP-I (0 ≤ x ≤ 1/2) and CNYP-II (0 ≤ y ≤ 1) solid solutions were analyzed by SEM and EDS. The PL spectra of the specimens were containing the predominant red peak of emission at 612 nm caused via the transition of 5 D 0 -7 F 2 , indicating that Eu 3+ occupies the low-symmetry center. Moreover, the site symmetry Eu 3+ occupied changed with the x/y value. The luminous intensity of Eu 3+ -doped CNYP-I (0 ≤ x ≤ 1/2) and CNYP-II (0 ≤ y ≤ 1) phosphors at 150°C maintained about 60% of room temperature. The representative compound CNYP-I (x = 1/3) was used as the red phosphor to prepare a near-UV based white LEDs along with Ra of 80.9 and CCT of 4100 K.

Charge compensation engineering for high-performance dolomite-type BaTi(BO3)2:Eu3+ red-emitting phosphor for backlight display applications with a wide color gamut

“…Unlike the BTB body, the introduction of Eu 3+ ions make the spectrum form obvious absorption peaks at 395 and 465 nm, which is caused by the 4f-4f transition of the Eu 3+ ion. 22 Then, the band gap of the BTB:xEu 3+ phosphors were estimated via the Kubelka-Munk and Tauc formula: 23 α / ð1 À RÞ 2 =2R and…”

Cationic composition engineering in double perovskite XLaLiTeO6:Eu3+(X = Ba, Sr, Ca, and Mg) toward efficient and thermally stable red luminescence for domestic white-LEDs

“…22 Another advantage of double perovskite is its highly flexible structure with multiple cationic occupation forms, and thus it can allow us to optimize the luminescent properties by composition engineering method. 23–28…”

“…22 Another advantage of double perovskite is its highly flexible structure with multiple cationic occupation forms, and thus it can allow us to optimize the luminescent properties by composition engineering method. [23][24][25][26][27][28] The double perovskite type (Ba, Sr)LaLiTeO 6 tellurates have been proven to be the reliable hosts for Eu 3+ dopants, but the luminescent efficiency and thermal stability of the phosphors are very weak. 29,30 In this work, cationic composition engineering by alkaline earth ion substitution is proposed to modify their luminescent properties.…”

Physicochemical Characterization of the Hybrid Molybdate–Tungstate Materials for Solid-State Lighting

“…Photoluminescent materials based on rare earth elements have been attractive for novel fluorescent probes, 1 effective spectral converters for solar cells, 2,3 used in an anticounterfeiting application, 4 optical sensors for oxygen detection, 5 and used in solid-state lighting, 3,6−8 general fluorescent lamps, energysaving lamps, and white light-emitting diodes (W-LEDs). 9−12 W-LEDs are the next-generation light source because of their high luminous efficiency, long lifetime, high thermal stability, 13,14 absence of pollution, 11,15,16 and low price. 17,18 For this reason, W-LEDs are a prospective replacement for conventional light sources.…”

“…Photoluminescent materials based on rare earth elements have been attractive for novel fluorescent probes, effective spectral converters for solar cells, , used in an anticounterfeiting application, optical sensors for oxygen detection, and used in solid-state lighting, ,− general fluorescent lamps, energy-saving lamps, and white light-emitting diodes (W-LEDs). − W-LEDs are the next-generation light source because of their high luminous efficiency, long lifetime, high thermal stability, , absence of pollution, ,, and low price. , For this reason, W-LEDs are a prospective replacement for conventional light sources. , Nowadays, commercial white LEDs available in the market are produced by combining a blue LED chip with yellow (YAG:Ce 3+ ) phosphors. Regrettably, this combination lacks a red component, rendering it poor quality for indoor lighting due to its high correlated color temperature (CCT > 6000 K) and low color rendering index (CRI, Ra < 80).…”