Energy transfer and color‐tunable emission in Ba₂Y₂Si₄O₁₃:Bi³⁺,Eu³⁺ phosphors

Abstract

Single‐composition Ba2Y2Si4O13:Bi3+,Eu3+ (BYSO:Bi3+,Eu3+) phosphors with color‐tunable and white emission were prepared by conventional high temperature solid‐state reaction method. The structural and luminescent properties of these phosphors were thoroughly investigated through X‐ray diffraction, photoluminescence, and decay curves. BYSO:Bi3+ phosphors show two excitation peaks at 342 and 373 nm, and give two emission peaks at 414 and 503 nm, respectively, indicating that there are two sites of Bi3+ in BYSO. The energy transfer from Bi3+ to Eu3+ was investigated in detail. Varied hues from blue (chromaticity coordinate [0.219, 0.350]) to white (0.288, 0.350) and orange‐red light (0.644, 0.341) can be generated by adjusting the content of Eu3+. Pure white light emission (0.311, 0.338) can be obtained under the excitation of 355 nm in BYSO:3%Bi3+,20%Eu3+ phosphor. Besides, BYSO:Bi3+,Eu3+ phosphors exhibit distinct thermal quenching properties, whose emission intensity at 473 K is 82.6% of that at 298 K. Our results indicate that BYSO:Bi3+,Eu3+ may be applied as conversion phosphors for n‐UV‐based W‐LEDs.

Recent Advances in Bismuth Ion‐Doped Phosphor Materials: Structure Design, Tunable Photoluminescence Properties, and Application in White LEDs

“…Reproduced with permission. [ 45 ] Copyright 2018, Wiley‐VCH. e) PL spectra of BaY 2 Si 3 O 10 :0.01Bi 3+ pumped by 330–380 nm excitation wavelengths.…”

“…Similarly, Bi 3+ ions can occupy two different Ba 3+ and Y 3+ crystallographic sites in Ba 2 Y 2 Si 4 O 13 host. [ 45 ] Figure 12d displays the PL spectra of Ba 2 Y 2 Si 4 O 13 :3%Bi 3+ phosphor at the excitation wavelengths of 340–370 nm. As the excitation wavelength increases, the PL intensity of 414 nm emission gradually increases, while 503 nm emission gradually decreases.…”

“…Figure 23g displays the PL spectra of Ba 2 Y 1.94 Si 4 O 13 :3%Bi 3+ (λ ex = 342 nm and λ ex = 373 nm) and PLE spectra of Ba 2 Y 1.6 Si 4 O 13 :20%Eu 3+ (λ em = 613 nm). [ 45 ] It is obvious that the spectral overlap between the broad emission of Bi 3+ and the sharp excitation peaks of Eu 3+ is large, which demonstrates that ET may occur from Bi 3+ to Eu 3+ . The PL spectra of Ba 2 Y 2(0.97− y ) Si 4 O 13 :3%Bi 3+ , y Eu 3+ ( y = 4%, 8%, 12%, 16%, 20%, 22%) samples with different Eu 3+ contents excited by 342 nm UV light (Figure 23h) also show the process of Bi 3+ → Eu 3+ ET.…”

“…Reproduced with permission. [ 45 ] Copyright 2018, Wiley‐VCH.…”

Near‐Unity Cyan‐Green Emitting Lead‐Free All‐Inorganic Cesium Copper Chloride Phosphors for Full‐Spectrum White Light‐Emitting Diodes

“…Phosphor‐converted white light‐emitting diodes (pc‐wLEDs) are rapidly becoming an indispensable lighting source for daily life because of their prominent characteristics, such as high efficiency, energy saving, long lifetime, environmental friendliness, compactness, etc. [ 1–4 ] Currently, commercial pc‐wLEDs are mainly produced by coating blue LED chips with the yellow‐emitting Y 3 Al 5 O 12 :Ce 3+ phosphor (YAG:Ce 3+ ). [ 5 ] However, this type of wLEDs shows a low color rendering index (CRI < 80) due to the absence of cyan and red components in the spectrum.…”