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.