Anionic Regulation toward Bi³⁺ Selective Occupation for Full-Spectrum White Light Emission

Abstract

An activator’s selective occupation of a host is of great significance for designing high-quality white light-emitting diode phosphors, while achieving a full-spectrum single-phase white light emission phosphor is challenging. In this study, a boron phosphate solid-solution Na2Y2(BO3)2–x (PO4) x O:0.005 Bi3+ (NYB2–x P x O:0.005 Bi3+) white phosphor was designed by selectively occupying Bi3+ activators in the mixed anionic groups. The substitutes of the anionic unit (BO3)3– by the (PO4)3– unit are supposed to force part of the Bi3+ ion to enter the Na lattice site, which produces an intense orange-red emission peaked at 590 nm. In parallel, spectral tuning from blue to white light and an internal quantum efficiency of 56.42% was obtained, and the thermal stabile luminescence intensity remains at 94.2% of the initial intensity after four heating–cooling cycles from 30 to 210 °C (luminescent intensity is 83.6% of room temperature (RT) at 150 °C, with excellent thermal stability and recovery performance). Finally, an excellent color rendering index (Ra = 90.8 and R9 = 85) was demonstrated for white light-emitting diode devices using only an NYB1.5P0.5O:0.005 Bi3+ phosphor and a near-ultraviolet (n-UV) 365 nm LED chip. This work delves into the different selective occupancy of Bi3+ ions and explores a new avenue for the design of phosphors for full-spectrum white light emission.

Color-resolved mechanoluminescence of Eu and Mn co-doped SrMg2(PO4)2

“…19 Similarly, Wu et al reported a Lu 3 Al 2 Ga 3 -O 12 :Tb 3+ ML material, where the electron transition of the Tb 3+ ion from 5 D 3 → 7 F 6-4 and 5 D 4 → 7 F 6-0 contributed two different emission bands respectively, and the ML color varied with the applied stress. 20 The aforementioned results suggest that effective realization of stress-sensitive color variations can be achieved by harnessing the diverse luminescence behaviors exhibited by activators under stress. Generally, the luminescence kinetics of activators in ML materials are significantly affected by changes in the local crystal field environment.…”

Realizing Near Infrared Mechanoluminescence Switch in LAGO:Cr Based on Oxygen Vacancy

“…Mechanoluminescence (ML) is the mechanical-photon conversion process of a material under mechanical stimuli such as impact, torsion, stretching, and friction. [1][2][3][4][5][6] In 1605, Bacon first observed the ML phenomenon by scraping sugar. [7] In 1966, Butler discovered the deformation luminescence phenomenon of alkali metal halides.…”

Multicolor Mechanoluminescence in Sr2Ga2GeO7: Pr3+ for Stress Sensing and Anticounterfeiting

“…Similar to transition metal ions, the electron transition selection rules for lanthanide ion are also closely related to the corresponding site symmetry and crystal field intensity. [ 10 ] With changes in the local crystal environment, the emission spectral distribution may change differently. Thereinto, Pr 3+ is featured with a 4f 2 shell, and due to the 13 multiplets in the Pr 3+ 4f 2 configuration and non‐4f states, Pr 3+ exhibits varied luminescence behaviors in different host lattices.…”