Abstract
The
exploitation
of
borate‐based
phosphors
is
garnered
tremendous
attention
in
w
LEDs.
Although
previous
research
provided
some
insights
into
borates
from
the
viewpoints
synthesis,
structure,
and
defect
evolutions,
their
photoluminescence
(PL)
with
dopants
still
insufficient
for
actual
application,
especially
on
aspects
efficiency/stability.
Herein,
to
alleviate
above
issues,
a
new
type
lesser‐known
high
symmetry
Ba
3
Y
2
B
6
O
15
(BYB)
codoped
Dy
3+
/Eu
are
synthesized
via
multistep
solid‐state
reaction
possessed
controllable
PL
based
n
UV
excitation,
defect‐induced
(self‐)
PL,
energy
transfer
(ET)
Eu
.
origin
blue
self‐PL
clarified
oxygen‐related
defects
optimized
adjusting
synthetic
atmosphere
(air/Ar)
(co)doping
control
content.
Thanks
dense
connectivity,
highly
symmetric
structure
perfectly
ordered
octahedral
sites
accommodation
Dy/Eu
ET,
“cool”
white
red
,
respectively,
show
efficiency
narrow
full
width
at
half
maximum
(fwhm).
phosphor
also
exhibits
excellent
thermal
stability
because
bandgap
low
electron‐phonon
coupling.
Finally,
high‐quality
phosphor‐converted
LED
(pc‐
LED)
device
assembled
remote
“capping”
packaging
by
adopting
BYB:
350
nm
chip.
Advanced Optical Materials,
Journal Year:
2025,
Volume and Issue:
unknown
Published: March 20, 2025
Abstract
Luminescence
intensity
decreasing
with
rising
temperature
is
a
common
phenomenon
called
thermal
quenching.
However,
the
Bi
3+
‐Eu
co‐doped
NaGd
2
Ga
3
Ge
O
12
(NGGG)
phosphor
exhibits
antithermal
quenching
luminescence
of
Eu
.
has
pair
thermally
coupled
energy
levels
(TCLs),
where
higher
level
P
1
and
lower
derived
from
metal‐to‐metal
charge‐transfer
(MMCT).
As
concentration
increases,
lifetime
decreases,
while
MMCT
remains
unchanged.
It
means
that
transfer
(ET)
only
happens
between
Interestingly,
excited,
emission
still
observed.
This
because
when
exciting
level,
as
upper
TCLs,
can
also
be
which
consequently
leads
to
Accordingly,
⁺
will
increased
show
coupling
process
enhanced
temperature.
Taking
advantage
unique
ET
⁺,
⁺‐Eu
NGGG
demonstrates
sensitivity
2.08%
K
−
¹
at
500
K,
distinct
most
fluorescence
thermometers
maximum
low
temperatures.
