With
the
development
of
white
light-emitting
diode
(LED)
technology,
near-infrared
(NIR)
phosphor-converted
(pc)
LED
is
becoming
a
new
emerging
light
source.
However,
due
to
lack
long
wavelength
components
phosphors,
application
NIR
pc-LED
restricted.
In
this
work,
continuous
ultra-broadband
emission
without
gap
in
850–950
nm
region
has
been
realized
Mg4Nb2O9
(MNO):Cr3+,
Yb3+
phosphor.
Meanwhile,
when
compared
MNO:Cr3+,
an
improved
internal
quantum
efficiency
(from
55.4%
72.6%)
and
thermal
stability
39%
63%
at
100
°C)
have
obtained
for
Yb3+,
which
attributed
combined
effect
efficient
energy
transfer
from
Cr3+
its
nearest
unique
levels
Yb3+.
The
performances
fabricated
devices
by
combining
with
460
chips
were
also
given,
results
demonstrate
that
phosphor
may
potential
practical
pc-LED.
Chemistry of Materials,
Год журнала:
2024,
Номер
36(9), С. 4654 - 4663
Опубликована: Май 1, 2024
Materials
emitting
near-infrared
(NIR)
light
play
a
crucial
role
in
the
development
of
phosphor-converted
light-emitting
diodes
(pc-LEDs)
for
applications
ranging
from
fundamental
science
like
spectroscopic
analysis
to
highly
applied
uses
night
vision
and
biological
imaging.
One
class
materials
that
has
garnered
significant
interest
these
technical
spaces
is
Cr3+-activated
garnets
due
their
high
efficiency
ability
operate
at
relatively
temperatures.
However,
limited
emission
beyond
800
nm
impedes
use
as
optimal
blue
LED-pumped
NIR-emitting
materials.
In
this
study,
we
present
new
garnet-type
NIR
phosphor,
Na2CaZr2Ge3O12:Cr3+,
addresses
challenge─the
material
exhibits
long-wavelength
(λem,max
=
832
nm)
good
thermal
quenching
resistance
while
maintaining
an
excellent
internal
quantum
(IQE
98%).
These
properties
are
attributed
crystal
environment
reconstruction,
where
structure
distortion
coupled
weak
field,
which
uncommon
most
rigid
phosphors.
Furthermore,
fabricated
pc-LED
devices
using
demonstrate
superior
performance
compared
with
employing
well-known
efficient
phosphors
operating
range.
The
source
subsequently
demonstrated
spanning
vision,
bioimaging,
nondestructive
analysis.
This
study
not
only
provides
insights
into
luminescence
garnet
desirable
but
also
highlights
practical
application
Advanced Optical Materials,
Год журнала:
2024,
Номер
12(17)
Опубликована: Март 2, 2024
Abstract
The
near‐infrared
(NIR)
persistent
luminescence
(PersL)
materials
have
attracted
widespread
attention
owing
to
the
unique
self‐sustained
light
with
good
penetrability.
Currently,
most
of
reported
NIR
PersL
are
activated
by
Cr
3+
.
Considering
potential
toxicity
chromium
ions,
there
is
an
urgent
requirement
explore
‐free
phosphors.
Herein,
a
novel
phosphor
Sr
2
LuSbO
6
:Fe
(SLSO:Fe
)
prepared
and
its
properties
systematically
studied.
Fe
‐activated
exhibits
long‐wavelength
emission
band
centered
at
890
nm
110
full‐width
half
maximum
(FWHM),
can
last
over
18
h.
shows
excellent
stability
even
after
being
dispersed
in
solutions
different
environments
for
7
days.
Furthermore,
emitted
penetrate
cm
thickness
beef,
evidencing
penetration
property.
This
work
provides
based
on
technological
applications
also
contributes
accelerate
development
new‐generation
‐doped
toward
versatile
applications.
Advanced Optical Materials,
Год журнала:
2023,
Номер
12(4)
Опубликована: Авг. 31, 2023
Abstract
Near‐infrared
(NIR)
phosphors
are
enablers
for
NIR
phosphor‐converted
light‐emitting
diodes
(pc‐LEDs).
However,
fewer
NIR‐emitting
with
both
high
internal/external
quantum
efficiency
(IQE/EQE)
and
thermal
stability
discovered,
which
obstructs
the
promotion
of
pc‐LEDs.
Herein,
by
partially
replacing
Al
3+
in
K‐β‐Al
2
O
3
:2Cr
Ga
,
photoluminescence
(PL)
intensity
solid
solution
K
1+δ
(Al
0.4
0.6
)
11
17
(KA
G
O:Cr)
phosphor
is
increased
2.75
1.25
times
that
end‐members
(KAO:Cr)
(KGO:Cr).
The
IQE/EQE
optimal
KA
O:Cr
reaches
88.9%/50.8%
(77.4%@150
°C).
PL
enhancement
due
to
Al/Ga‐6O
octahedral
volume
distortion
variation
caused
substitution
1‐y
,Ga
y
O:Cr),
leads
forbidden
d–d
transition
being
broken
crystal
field
strength
varied.
Finally,
a
pc‐LED
device
fabricated
based
on
blue
chip
an
electro‐optical
16.3%
under
drive
current
100
mA.
Meanwhile,
non‐destructive
detection
plant
germination
applications
demonstrated.
These
results
prove
promising
diverse
applications.
Advanced Optical Materials,
Год журнала:
2023,
Номер
12(11)
Опубликована: Дек. 8, 2023
Abstract
Cr
3+
‐doped
phosphors
are
highly
recognized
in
various
fields
for
their
remarkable
luminous
efficiency
and
spectral
flexibility,
including
modern
agriculture
horticulture.
However,
the
shortage
of
suitable
far‐red
LED
devices
has
inhibited
popularization
plant
lighting.
Herein,
an
innovative
phosphor
Ca
2
YAl
3
Ge
O
12
:Cr
(CYAG:Cr
),
achieving
a
broad
emission
at
770
nm
upon
450
blue
light
excitation
is
designed.
The
optimal
CYAG:Cr
exhibits
high
internal
quantum
yield
78.2%
low
thermal‐quenching
behavior
85%@373
K.
Thus,
fabricated
phosphor‐converted
LEDs
(pc‐LEDs)
lighting
have
output
power
33.3
mW
photovoltaic
conversion
11.5%
100
mA.
potential
assessed
by
supplementing
Italian
lettuce
with
pc‐LEDs,
biomass
significantly
increased
33%.
successful
development
provides
high‐quality
option
further
stimulates
new
plant‐lighting
phosphors.
Laser & Photonics Review,
Год журнала:
2024,
Номер
18(5)
Опубликована: Янв. 8, 2024
Abstract
Near‐infrared
(NIR)
light
sources
have
gained
immense
popularity
in
recent
years
due
to
their
wide
range
of
applications
various
fields,
including
spectroscopy
and
biomedical
imaging.
However,
the
limited
emission
bandwidth
NIR
phosphors
is
a
significant
bottleneck
development.
Here,
novel
strategy
reported
broaden
by
awakening
dumb
site.
Na
4
M
3
Ta(PO
)
6
:
Cr
3+
(
=
Al
,
Ga
In
phosphor
synthesized,
which
exhibits
greatly
broadened
from
134
232
nm.
Structural
spectral
analysis
reveals
that
NaO
octahedral
site
has
severe
t
2g
‐type
distortion,
making
it
for
.
By
introducing
larger
at
site,
angular
distortion
decreases
normal
range,
enabling
luminescence
again.
Along
with
bandwidth,
peak
also
redshifts
802
977
nm,
giving
advantages
applications.
Interestingly,
awakened
shows
even
better
properties
than
original
M/TaO
These
findings
reveal
insight
into
could
potentially
revolutionize
design
phosphors.
Journal of Advanced Ceramics,
Год журнала:
2024,
Номер
13(3), С. 354 - 363
Опубликована: Янв. 29, 2024
Near-infrared
(NIR)
phosphor-converted
light-emitting
diodes/laser
diodes
(LEDs/LDs)
are
prospective
lighting
sources
for
NIR
spectroscopy.
However,
developing
a
phosphor
material
with
desired
thermal
robustness
and
high
photoelectric
efficiency
is
crucial
challenge
its
applications.
In
this
work,
based
on
the
cationic
radius
matching
effect,
series
of
(Lu,Y)3(Al,Sc,Cr)2Al3O12
ceramics
(LuYScCr
NIR-PCs)
were
fabricated
via
vacuum
sintering.
An
excellent
stability
(95%@150
oC)
was
obtained
in
prepared
NIR-PC,
owing
to
weak
electron
phonon
coupling
effect
(small
Huang
Rhys
factor).
Being
excited
at
460
nm,
NIR-PCs
realized
broadband
emission
(650-850
nm)
an
IQE
60.68
%.
Combining
LED/LD
chips,
maximum
output
power
encapsulated
LED
prototype
447
mW
@
300
mA
as
18.6
%
180
mA,
LD
814mW
2.5
A.
The
working
temperatures
70.8
oC
(LED)
102.8
3
A
(LD),
respectively.
Finally,
applied
food
detection
verified
study,
demonstrating
anticipated
application
prospects
future.
Inorganic Chemistry,
Год журнала:
2024,
Номер
63(5), С. 2655 - 2662
Опубликована: Янв. 22, 2024
In
an
increasing
manner,
near-infrared
phosphor-converted
light-emitting
diodes
(NIR
pc-LEDs)
are
considered
to
be
exemplary
light
sources
owing
their
notable
attributes
of
elevated
output
power,
economical
nature,
and
exceptional
portability.
NIR
phosphors
critical
components
pc-LEDs.
Herein,
we
report
a
novel
blue
excitable
phosphor
CaLu2ZrScAl3O12:Cr3+
(CLZSA:Cr3+)
as
crucial
efficient
broadband
emitter.
The
CLZSA:Cr3+
displays
intense
emission
peaking
at
776
nm
with
full
width
half-maximum
(fwhm)
140
nm.
designed
material
also
exhibits
superior
resistance
thermal
quenching,
the
intensity
423
K
remains
80%
that
room
temperature.
constructed
pc-LED
device
based
on
demonstrates
high
total
power
68.4
mW
drive
current
100
mA,
along
photoelectric
conversion
efficiency
23.0%.
Impressively,
high-power
pc-LEDs
utilized
for
remote
control
non-invasive
detection,
resulting
in
excellent
performance
remarkable
achievement.
