Abstract
Near‐infrared
(NIR)
phosphor‐converted
light‐emitting
diodes
(pc‐LEDs)
are
considered
as
promising
next‐generation
light
sources
for
optoelectronic
and
biomedical
applications.
Nevertheless,
NIR
phosphors
with
large
bandwidths,
long
emission
peaks,
high
external
quantum
efficiencies
(EQEs)
valuable
thermal
stabilities
challenging
to
develop.
Herein,
this
study
reports
a
novel
gallium
germanate
host,
Ga
3
Al
Ge
2
O
13
(GAGO),
bandgap
rigid
host
lattice
Cr
3+
ion
doping.
The
blue
LED
excitable
GAGO:0.012Cr
phosphor
can
produce
broadband
maximum
intensity
at
816
nm
full‐width
half‐maximum
(FWHM)
of
187
nm.
Notably,
the
also
exhibits
an
excellent
EQE
35.8%
perfect
stability
(I
423
K
/I
298
=
67.4%).
Moreover,
attractive
afterglow
duration
more
than
24
h
is
achieved
in
GAGO:0.004Cr
phosphor.
type
origin
traps
discussed,
possible
persistent
luminescent
(LPL)
mechanism
proposed.
Finally,
pc‐LED
based
on
fabricated.
results
demonstrate
that
obtained
show
great
potential
use
night
vision,
nondestructive
detection,
bioimaging
information
encryption.
This
provides
new
insight
into
development
materials
efficiency,
good
extraordinary
performance.
Chemical Reviews,
Journal Year:
2022,
Volume and Issue:
122(13), P. 11474 - 11513
Published: May 22, 2022
Light-emitting
diodes
(LEDs)
are
attracting
considerable
attention
around
the
world.
Phosphor
materials,
as
crucial
color-converted
components,
play
central
roles
in
LED
development.
The
demands
for
phosphor
materials
have
become
increasingly
stringent
over
past
decades,
from
high
brightness
to
narrowband
emission
or
function-dependent
spectrum
engineering.
Although
substantial
progress
has
been
made
currently
developed
simultaneously
satisfying
all
requirements
high-level
applications
remains
challenging.
In
this
review,
we
aim
provide
a
comprehensive
understanding
of
development
different
generations
and
elucidate
key
designed
mechanisms
concerning
activators
host
structures
fulfill
aforementioned
aspects.
We
highlight
developments
through
classification
luminescence,
thermal
stability,
color
gamut,
broadband
near-infrared.
also
focus
on
elucidating
generations.
Furthermore,
future
perspectives
about
micro-LED
nanoluminescent
provided.
This
study
opens
up
an
avenue
designing
luminescent
future.
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.
Angewandte Chemie International Edition,
Journal Year:
2021,
Volume and Issue:
60(26), P. 14644 - 14649
Published: April 6, 2021
Abstract
Near‐infrared
(NIR)‐emitting
phosphor
materials
have
been
extensively
developed
for
optoelectronic
and
biomedical
applications.
Although
Cr
3+
‐activated
phosphors
widely
reported,
it
is
challenging
to
achieve
ultra‐broad
tunable
NIR
emission.
Here,
a
new
ultra‐broadband
NIR‐emitting
LiIn
2
SbO
6
:Cr
with
emission
peak
at
965
nm
full‐width
half
maximum
of
217
reported.
Controllable
tuning
from
892
achieved
by
chemical
unit
cosubstitution
[Zn
2+
–Zn
]
[Li
+
–In
],
which
can
be
ascribed
the
upshift
4
T
2g
energy
level
due
strengthened
crystal
field.
Moreover,
greatly
enhanced,
FWHM
reaches
235
nm.
The
as‐prepared
luminescent
demonstrated
potential
in
night‐vision
spectroscopy
techniques.
This
work
proves
feasibility
strategy
‐doped
phosphors,
stimulate
further
studies
on
emission‐tunable
materials.
Inorganic Chemistry Frontiers,
Journal Year:
2020,
Volume and Issue:
7(6), P. 1467 - 1473
Published: Jan. 1, 2020
LaMgGa11O19:Cr3+
phosphor
was
synthesized
successfully,
showing
broadband
NIR
emission
centered
at
∼770
nm,
high
efficiency
and
excellent
thermal
quenching
resistance
for
pc-LEDs.
ACS Applied Materials & Interfaces,
Journal Year:
2021,
Volume and Issue:
13(15), P. 18274 - 18282
Published: April 8, 2021
Recently,
trivalent
chromium
ion
doped
phosphors
have
exhibited
significant
application
potential
in
broadband
near-infrared
(NIR)
phosphor-converted
light-emitting
diodes
(pc-LEDs).
However,
developing
an
NIR
phosphor
with
both
broad
emission
bandwidth
and
excellent
luminescence
thermal
stability
is
still
a
great
challenge.
Here,
we
demonstrate
phosphor,
ScF3:Cr3+,
which
can
fulfill
conditions
simultaneously.
The
prepared
show
the
range
of
700
to
1100
nm,
full
width
at
half-maximum
(FWHM)
140
nm
peaking
853
nm.
These
also
(the
intensity
ScF3:Cr3+
keeps
85.5%
150
°C
compared
value
room
temperature).
An
pc-LED
based
on
blue
LED
chips
was
fabricated
tested.
results
that
yield
strong
emission.
This
work
not
only
provides
promising
for
pc-LEDs
but
has
important
guiding
significance
effect
synthesis
properties
Cr3+-doped
fluorides.
Abstract
The
growing
demand
for
spectroscopy
applications
in
the
areas
of
agriculture,
retail
and
healthcare
has
led
to
extensive
research
on
infrared
light
sources.
ability
phosphors
absorb
blue
from
commercial
LED
convert
excitation
energy
into
long-wavelength
luminescence
is
crucial
design
cost-effective
high-performance
phosphor-converted
LEDs.
However,
lack
ideal
blue-pumped
short-wave
(SWIR)
with
an
emission
peak
longer
than
900
nm
greatly
limits
development
SWIR
LEDs
using
converter
technology.
Here
we
have
developed
a
series
SWIR-emitting
materials
high
efficiency
excellent
thermal
stability
by
co-doping
Cr
3+
-Yb
ion
pairs
Lu
0.2
Sc
0.8
BO
3
host
materials.
Benefitting
strong
absorption
waveband
very
efficient
→Yb
transfer,
as-synthesized
:Cr
,Yb
phosphor
emits
intense
900–1200
Yb
under
at
~460
nm.
optimized
presents
internal
quantum
yield
73.6%
intensity
100
°C
can
still
keep
88.4%
starting
value
25
°C.
prototype
device
based
exhibits
exceptional
performance,
delivering
radiant
power
18.4
mW
9.3%
blue-to-SWIR
conversion
5.0%
electricity-to-SWIR
120
mA
driving
current.
Moreover,
illumination
high-power
LED,
covert
information
identification
night
vision
lighting
been
realized,
demonstrating
bright
prospect
practical
applications.
Journal of Materials Chemistry C,
Journal Year:
2020,
Volume and Issue:
9(1), P. 164 - 172
Published: Nov. 10, 2020
GdAl3(BO3)4:Cr3+is
used
to
fabricate
a
NIR-pc-LED
that
shows
promise
for
plant
lighting
and
applications
in
the
nondestructive
analysis
of
agricultural
products.
Abstract
Broadband
near‐infrared
(NIR)
phosphor‐converted
(pc)
LED
is
promising
next‐generation
tiny
light
source
for
smart
and
broadband
NIR
spectroscopy
technology.
However,
phosphors
suffer
from
challenges
in
terms
of
low
quantum
efficiency
bandwidth.
By
selecting
a
host
that
has
big
bandgap
weakening
coupling
effect
among
Cr
3+
,
novel
LiGaP
2
O
7
:Cr
(LGAP:Cr
)
phosphor
high
external
(28.3%)
discovered.
Under
≈450
nm
excitation,
LGAP:Cr
shows
broad
emission
700
to
1100
with
bandwidth
≈170
nm.
Importantly,
the
fabricated
pcLED
demonstrates
bright
an
excellent
performance
night
vision.
The
results
promise
use
high‐performance
employs
only
one
blue
chip.
Advanced Optical Materials,
Journal Year:
2022,
Volume and Issue:
11(3)
Published: Dec. 5, 2022
Abstract
Development
of
chromium‐doped
luminescent
materials
is
pertinent
to
many
emerging
applications,
ranging
from
agriculture,
food
industry
noninvasive
health
monitoring.
The
fundamental
importance
chromium‐activated
in
the
field
optics
and
biomedicine
makes
rapid
development
novel
relevant
applications.
Herein,
recent
advances
on
luminescence
principle
photoluminescence
(PL)
optimization
for
Cr
3+
‐activated
together
with
their
potential
applications
are
reviewed.
different
types
most
recently
developed
‐doped
design
principles
systematically
summarized.
associations
between
crystal
structure
near‐infrared
(NIR)
PL
properties,
as
well
performance‐evaluating
parameters
introduced
examples
known
NIR
emitting
phosphors,
which
will
be
helpful
explore
future
materials.
Based
control,
site
engineering,
electron–phonon
coupling,
several
efficient
strategies
optimizing
performances
including
bandwidth,
thermal
stability,
quantum
efficiency
proposed.
Then,
fields
analysis,
night
vision,
information
encryption,
optical
sensors
surveyed.
Finally,
challenges
promising