Abstract
The
burgeoning
phosphor‐converted
near‐infrared
light‐emitting
diodes
(pc‐NIR
LEDs)
have
important
applications
in
special
illumination
and
spectroscopy
analysis.
However,
the
development
of
efficient
NIR‐emitting
phosphors
with
high
performance
is
still
a
challenge.
In
this
work,
chemical
unit
co‐substitution
strategy
proposed
to
realize
excitation
transition
regulation
successfully
achieve
high‐performance
NIR
luminescence
Ca
3‐
y
Na
Mg
1‐
Sb
2‐
x
Al
2+
O
12
:
Cr
3+
(0
≤
0.05,
0
1)
garnet‐type
solid
solution
phosphors.
Through
modulation
from
4
A
2
ground
state
T
1
(
P)
F)
state,
intensity
at
blue
light
region
largely
enhanced
by
25.6
times.
Moreover,
efficiency
thermal
stability
are
improved,
optimal
internal
quantum
90.6%
97%@423
K,
without
any
flux‐assisted
sintering
or
reduction
atmosphere
protection.
structure
induced
small
Stokes
shift,
weak
electron‐phonon
coupling
effect,
decreased
non‐radiative
responsible
for
excellent
performance.
Finally,
pc‐LED
fabricated
photoelectric
efficiencies
18.7%@100
mA
output
powers
63
mW@100
mA,
presenting
potential
nondestructive
defect
detection,
veins
imaging,
night
vision
surveillance.
Abstract
Cr
3+
/Cr
4+
‐activated
near‐infrared
(NIR)
luminescent
materials
have
attracted
extensive
attention
owing
to
their
tunable
emission
wavelength
and
widespread
applications
in
plant
growth,
food
analysis,
biomedical
imaging,
night
vision,
so
on.
Plenty
of
excellent
NIR
are
developed
by
introducing
ion
various
inorganic
hosts.
Herein,
the
effect
crystal
field
on
luminescence
combining
Tanabe–Sugano
energy
level
diagram
configuration
coordinate
model
is
discussed.
Research
progress
‐doped
materials,
including
phosphors
designed
from
structural
models
with
octahedral,
tetrahedral,
other
coordination
types,
then
outlined.
The
properties
more
than
200
kinds
summarized.
In
particular,
several
strategies
for
tuning
wavelength,
broadening
band,
enhancing
efficiency,
improving
thermal
stability,
listed.
Finally,
current
challenges
future
prospects
research
presented.
This
review
will
contribute
a
deeper
understanding
not
only
mechanism
but
also
chromium‐doped
as
develop
better
performance
explore
applications.
Chemistry of Materials,
Journal Year:
2022,
Volume and Issue:
34(18), P. 8418 - 8426
Published: Sept. 15, 2022
Broadband
near-infrared
(NIR)
light
source
based
on
phosphor-converted
light-emitting-diode
(pc-LED)
is
crucial
for
applications
in
medical
diagnosis,
food
quality
analysis,
and
night
vision
fields,
motivating
the
development
of
highly
efficient
thermal
robust
NIR
phosphor
materials.
Herein,
a
novel
Cr3+-doped
garnet
Y3In2Ga3O12:Cr3+
emerges
from
fundamental
study
Ln3In2Ga3O12
(Ln
=
La,
Gd,
Y,
Lu)
family.
Upon
450
nm
excitation,
this
material
presents
broadband
emission
covering
650–1100
with
peak
located
at
760
full
width
half
maximum
125
nm.
This
also
possesses
an
ultrahigh
internal
quantum
efficiency
(IQE
91.6%)
absorption
(AE
46.6%),
resulting
external
as
high
42.7%.
Moreover,
intensity
150
°C
maintains
100%
initial
intensity,
showing
rare
zero-thermal-quenching
property.
Fabricating
pc-LED
device
by
using
material,
excellent
output
power
68.4
mW
photoelectric
15.9%
under
mA
driving
current
can
be
obtained,
which
exhibits
much
better
performance
than
devices
fabricated
some
reported
Therefore,
work
not
only
provides
ultraefficient
thermally
spectroscopy
application
but
contributes
to
foundation
design
rules
materials
performance.
Achievement
of
high
photoluminescence
quantum
efficiency
and
thermal
stability
is
challenging
for
near-infrared
(NIR)-emitting
phosphors.
Here,
we
designed
a
"kill
two
birds
with
one
stone"
strategy
to
simultaneously
improve
the
NIR-emitting
Ca3Y2-2x(ZnZr)xGe3O12:Cr
garnet
system
by
chemical
unit
cosubstitution,
revealed
universal
structure-property
relationship
luminescence
optimization
mechanism.
The
cosubstitution
[Zn2+-Zr4+]
[Y3+-Y3+]
played
critical
role
as
reductant
promote
valence
transformation
from
Cr4+
Cr3+,
resulting
reconstruction
octahedral
sites
Cr3+.
introduction
also
contributed
rigid
crystal
structure.
These
aspects
together
realized
internal
96%
excellent
89%@423
K.
Moreover,
information
encryption
"burning
after
reading"
was
achieved
based
on
different
resistance
phosphors
acid.
developed
phosphor-converted
light-emitting
diode
demonstrated
promising
applications
in
bio-tissue
imaging
night
vision.
This
work
provides
new
perspective
developing
high-performance
phosphor
materials.
Inorganic Chemistry,
Journal Year:
2023,
Volume and Issue:
62(10), P. 4220 - 4226
Published: March 1, 2023
Broadband
near-infrared
(NIR)
phosphors
are
the
critical
component
of
phosphor
converted
NIR
light-emitting
diode
(LED)
light
sources.
However,
there
still
a
lack
with
excellent
external
quantum
efficiency
(EQE)
and
thermal
stability.
Here,
we
report
highly
efficient
broadband
Y3Ga3MgSiO12:
Cr3+.
The
optimized
yields
an
internal
(IQE)
EQE
79.9
33.7%,
respectively.
integrated
emission
intensity
remains
at
84.4%
that
room
temperature
when
heated
to
423
K.
A
LED
lamp
was
made
by
combining
as-prepared
blue
InGaN
chip,
which
shows
output
power
89.8
mW
photoelectric
conversion
17.1%
driven
525
input
power.
Our
research
provides
promising
high
for
source.
Advanced Optical Materials,
Journal Year:
2023,
Volume and Issue:
11(21)
Published: June 7, 2023
Abstract
Cr
3+
‐activated
Gd
3
Ga
5
O
12
garnet
(GGG:Cr
)
near‐infrared
(NIR)
phosphors
have
shown
promising
applications
in
regulating
plant
growth.
However,
the
low
external
quantum
efficiency
(EQE)
results
a
wall‐plug
(WPE)
of
phosphor‐converted
light‐emitting
diodes
(pc)‐LEDs
only
≈15%.
Herein,
an
easy
strategy
to
improve
luminescent
properties
GGG:Cr
phosphor
is
reported.
Through
optimization
synthesized
technology,
EQE
enhanced
43.6%.
Remarkably,
fabricated
pc‐LEDs
achieve
WPE
as
high
34.3%.
These
demonstrate
significant
advancement
development
and
NIR
materials
pc‐LED
devices.
Advanced Materials,
Journal Year:
2023,
Volume and Issue:
36(9)
Published: Nov. 8, 2023
Abstract
There
is
strong
demand
for
ultraefficient
near‐infrared
(NIR)
phosphors
with
adjustable
emission
properties
next‐generation
intelligent
NIR
light
sources.
Designing
large
full‐width
at
half‐maximum
(FWHM)
variations
challenging.
In
this
study,
novel
near‐ultraviolet
light‐emitting
diode
(LED)‐excited
phosphors,
MgAlGa
0.7
B
0.3
O
4
:Cr
3+
(MAGBO:Cr
),
three
centers
achieve
ultra‐narrowband
(FWHM
=
29
nm)
to
ultra‐broadband
260
increasing
Cr
concentration.
Gaussian
fitting
and
decay
time
analysis
reveal
the
alteration
in
FWHM,
which
attributed
energy
transfer
occurring
between
centers.
The
distinct
thermal
quenching
behaviors
of
are
revealed
through
temperature‐dependent
times.
phosphor
MAGBO:0.05Cr
exhibits
high
stability
(85%,
425
K)
exceptional
external
quantum
efficiency
68.5%.
An
phosphor‐converted
LED
(pc‐LED)
fabricated
using
phosphor,
exhibiting
a
remarkable
output
power
136
mW
600
mA
pc‐LEDs.
This
study
describes
preparation
highly
efficient
provides
further
understanding
tunable
vital
high‐performance
versatile
applications.
Advanced Optical Materials,
Journal Year:
2023,
Volume and Issue:
11(7)
Published: Jan. 19, 2023
Abstract
Broadband
near‐infrared
(NIR)
phosphors
have
recently
received
considerable
attention
in
spectroscopy
technology
fields,
but
designing
inexpensive,
emission
peaks
centered
above
800
nm,
and
multimodal
broadband
NIR
luminescence
material
still
remains
a
great
challenge.
Here,
by
selecting
stannate
compound
Mg
2
SnO
4
(MSO)
as
the
host,
kind
of
phosphor
MSO:Cr
3+
with
multimode
properties
is
reported.
The
designed
exhibits
an
peaking
at
nm
full‐width
half
maximum
180
(≈2730
cm
−1
).
site
occupation
Cr
MSO
unraveled
density
functional
theory
calculation.
constructed
light‐emitting
device
based
on
displays
high
output
power
187.19
mW@100
mA
remarkable
photoelectric
efficiency
13.67%,
its
multifunctional
applications
information
encryption,
non‐destructive
detection,
so
are
also
demonstrated.
Additionally,
through
defect
reconstruction,
presents
superior
persistent
(PersL)
PersL
duration
time
longer
than
50
h.
This
work
provides
feasible
strategy
to
develop
intelligent
optical
integrated
low‐cost
compounds
host
toward
versatile
such
detection
bioimaging.
Inorganic Chemistry Frontiers,
Journal Year:
2023,
Volume and Issue:
10(7), P. 2197 - 2205
Published: Jan. 1, 2023
Enhanced
and
broadened
NIR
luminescence
was
realized
in
a
Gd
2−
x
Al
GaSbO
7
:Cr
3+
phosphor
by
→
cation
substitution.
Its
application
as
an
emitting
converter
for
LEDs
confirmed.
Chemistry of Materials,
Journal Year:
2024,
Volume and Issue:
36(9), P. 4654 - 4663
Published: May 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
Journal of Materials Chemistry C,
Journal Year:
2024,
Volume and Issue:
12(26), P. 9716 - 9732
Published: Jan. 1, 2024
This
work
investigates
the
important
role
of
structural
rigidity
and
defect
related
dynamics
a
promising
garnet
phosphor
with
robust
thermal
stability
for
efficient
NIR
pc-LED
devices.