Chemical Reviews,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 9, 2025
Fluorescence
emitters
with
a
multiple-resonant
(MR)
effect
have
become
research
hotspot.
These
MR
mainly
consist
of
polycyclic
aromatic
hydrocarbons
boron/nitrogen,
nitrogen/carbonyl,
and
indolocarbazole
frameworks.
The
staggered
arrangement
the
highest
occupied
molecular
orbital
lowest
unoccupied
facilitates
MR,
resulting
in
smaller
internal
reorganization
energy
narrower
emission
bandwidth.
Optimal
charge
separation
suppresses
gap
between
singlet
triplet
excited
states,
favoring
thermally
activated
delayed
fluorescence
(TADF).
MR-TADF
materials,
due
to
color
purity
high
efficiency,
are
excellent
candidates
for
organic
light-emitting
diodes.
Nevertheless,
significant
challenges
remain;
particular,
limitation
imposed
by
alternated
core
configuration
hinders
their
diversity
versatility.
Most
existing
materials
concentrated
blue-green
range,
only
few
red
near-infrared
spectra.
This
review
provides
timely
comprehensive
screening
from
pioneering
work
present.
Our
goal
is
gain
understandings
structure-performance
relationship
both
basic
advanced
perspectives.
Special
emphasis
placed
on
exploring
correlations
chemical
structure,
photophysical
properties
electroluminescent
performance
depth
breadth
an
aim
promote
future
development
emitters.
Advanced Optical Materials,
Год журнала:
2022,
Номер
10(22)
Опубликована: Сен. 23, 2022
Abstract
Organic
thermally
activated
delayed
fluorescence
(TADF)
materials
have
attracted
significant
research
interest
in
the
field
of
organic
electronics
because
their
inherent
advantage
100%
exciton
utilization
capability
light‐emitting
diodes
(OLEDs)
without
use
noble
metals.
However,
despite
high
internal
electroluminescence
quantum
efficiencies
approaching
unity,
broad
emission
spectra
with
sizable
full
width
at
half
maxima
(FWHM;
60–100
nm)
present
a
critical
issue
that
must
be
solved
for
application
ultrahigh‐definition
OLED
displays.
Recently,
new
paradigm
TADF
featuring
multiple
resonance
(MR)
effect
based
on
heteroatom‐doped
polycyclic
aromatic
frameworks,
referred
to
as
MR‐TADF
materials,
has
emerged
and
garnered
considerable
owing
remarkable
features
efficient
narrowband
emissions
extremely
small
FWHMs
(≤30
nm).
Currently,
occupy
prominent
position
cutting‐edge
from
both
chemical
physical
perspectives.
This
review
article
focuses
recent
progress
emissive
systems
perspective
molecular
design,
photophysical
properties,
performance
OLEDs.
The
current
status
future
prospects
this
advanced
material
technology
are
discussed
comprehensively.
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
61(30)
Опубликована: Май 10, 2022
Highly
efficient
circularly
polarized
luminescence
(CPL)
emitters
with
narrowband
emission
remain
a
formidable
challenge
for
OLEDs
(CP-OLEDs).
Here,
promising
strategy
developing
chiral
concurrently
featuring
multi-resonance
thermally
activated
delayed
fluorescence
(MR-TADF)
and
electroluminescence
(CPEL)
is
demonstrated
by
the
integration
of
molecular
rigidity,
central
chirality
MR
effect.
A
pair
green
denoted
as
(R)-BN-MeIAc
(S)-BN-MeIAc
designed.
Benefited
rigid
quasi-planar
MR-framework,
enantiomers
not
only
display
mirror-image
CPL
spectra,
but
also
exhibit
TADF
properties
high
photoluminescence
quantum
yield
96
%,
narrow
FWHM
30
nm,
horizontal
dipole
orientation
90
%
in
doped
film.
Consequently,
enantiomer-based
CP-OLEDs
achieved
excellent
external
efficiencies
37.2
very
low
efficiency
roll-off,
representing
highest
device
all
reported
CP-OLEDs.
Advanced Functional Materials,
Год журнала:
2023,
Номер
33(50)
Опубликована: Авг. 7, 2023
Abstract
Multi‐resonance
thermally
activated
delayed
fluorescence
(MR‐TADF)
emitters
have
drawn
considerable
attention
because
of
their
remarkable
optoelectronic
properties
high
emission
efficiency
and
narrow
profile,
represent
an
active
subject
cutting‐edge
research
in
the
organic
electroluminescence
(EL).
However,
slow
reverse
intersystem
crossing
(RISC)
rate
MR‐TADF
emitter
caused
by
large
energy
gap
(Δ
E
ST
)
small
spin‐orbit
coupling
(SOC)
matrix
elements
between
singlet
triplet
excited
states
limits
further
development
EL
devices.
Currently,
innovative
molecular
design
strategies
been
developed
including
heavy
atom
integration,
π‐extended
MR
framework
metal
perturbation,
so
on
to
improve
RISC
process
for
high‐performance
Here,
overview
is
presented
recent
progress
with
fast
(
>
10
−5
s
−1
),
particular
design,
properties,
device
performance
light‐emitting
diodes
(OLEDs),
which
intends
systematize
knowledge
this
thriving
highly
efficient
emitters.
Finally,
challenges
future
prospects
materials
are
discussed
comprehensively.
Advanced Materials,
Год журнала:
2023,
Номер
35(42)
Опубликована: Июль 18, 2023
Abstract
Advanced
circularly
polarized
multiple‐resonance
thermally
activated
delayed
fluorescence
(CP‐MR‐TADF)
materials
synergize
the
advantages
of
luminescence
(CPL),
narrowband
emission,
and
TADF
characteristic,
which
can
be
fabricated
into
highly
efficient
organic
light‐emitting
diodes
(CP‐OLEDs)
with
high
color
purity,
directly
facing
urgent
market
strategic
demand
ultrahigh‐definition
3D
displays.
In
this
work,
based
on
an
edge‐topology
molecular‐engineering
(ETME)
strategy,
a
pair
high‐performance
CP‐MR‐TADF
enantiomers,
(
P
M
)‐BN‐Py,
is
developed,
merges
intrinsically
helical
chirality
MR
framework.
The
optimized
CP‐OLEDs
)‐BN‐Py
emitters
newly
developed
ambipolar
transport
host
PhCbBCz
exhibit
pure
green
emission
sharp
peaks
532
nm,
full‐width
at
half‐maximum
(FWHM)
37
Commission
Internationale
de
L'Eclairage
(CIE)
coordinates
(0.29,
0.68).
Importantly,
they
achieve
remarkable
maximum
external
quantum
efficiencies
(EQEs)
30.6%
29.2%,
clear
electroluminescence
(CPEL)
signals
dissymmetry
factors
g
EL
s)
−4.37
×
10
−4
+4.35
for
respectively.
Advanced Materials,
Год журнала:
2023,
Номер
36(1)
Опубликована: Ноя. 14, 2023
Abstract
Helicenes
exhibit
substantial
potential
as
circularly
polarized
luminescence
(CPL)
active
molecules.
However,
their
application
in
organic
light‐emitting
diodes
(CP‐OLEDs)
is
typically
hindered
by
the
challenge
of
integrating
both
high
color
purity
and
efficient
triplet‐harvesting
capability,
particularly
blue
spectral
region.
Herein,
a
series
hetero[6]helicene‐based
emitters
that
strategically
engineered
through
helical
extension
deep‐blue
double‐boron‐based
multiple
resonance
thermally
activated
delayed
fluorescence
(MR‐TADF)
motif,
introduced.
Importantly,
does
not
cause
apparent
structural
deformation
or
perturb
frontier
molecular
orbitals;
thus,
preserving
emission
MR‐TADF
characteristics
parent
molecule.
This
approach
also
leads
to
reduced
reorganization
energy,
resulting
with
narrower
linewidth
higher
photoluminescence
quantum
yield.
Further,
motif
enhances
racemization
barrier
improved
CPL
performance
dissymmetry
factor
values
up
1.5
×
10
−3
.
Exploiting
these
merits,
devices
incorporating
chiral
dopants
demonstrate
within
Broadcast
Service
Television
2020
color‐gamut
range,
record
external
efficiencies
(EQEs)
29.3%,
have
distinctive
electroluminescence
(CPEL)
signals.
Overall,
authors’
findings
underscore
promising
strategy
for
designing
narrowband
chiroptical
materials
advancing
high‐definition
displays.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(18)
Опубликована: Фев. 21, 2024
The
intrinsic
helical
π-conjugated
skeleton
makes
helicenes
highly
promising
for
circularly
polarized
electroluminescence
(CPEL).
Generally,
carbon
undergo
low
external
quantum
efficiency
(EQE),
while
the
incorporation
of
a
multi-resonance
thermally
activated
delayed
fluorescence
(MR-TADF)
BN
structure
has
led
to
an
improvement.
However,
reported
B,N-embedded
all
show
dissymmetry
factors
(g
Journal of Materials Chemistry C,
Год журнала:
2023,
Номер
11(20), С. 6471 - 6511
Опубликована: Янв. 1, 2023
MR-TADF
emitters
with
narrow
emission
have
been
developed
and
are
expected
to
become
fourth-generation
for
HD-OLEDs,
molecular
design
guidelines
commercial
prospects
outlined
in
this
review.
Chemical Reviews,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 12, 2024
Since
the
seminal
report
by
Adachi
and
co-workers
in
2012,
there
has
been
a
veritable
explosion
of
interest
design
thermally
activated
delayed
fluorescence
(TADF)
compounds,
particularly
as
emitters
for
organic
light-emitting
diodes
(OLEDs).
With
rapid
advancements
innovation
materials
design,
efficiencies
TADF
OLEDs
each
primary
color
points
well
white
devices
now
rival
those
state-of-the-art
phosphorescent
emitters.
Beyond
electroluminescent
devices,
compounds
have
also
found
increasing
utility
applications
numerous
related
fields,
from
photocatalysis,
to
sensing,
imaging
beyond.
Following
our
previous
review
2017
(
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Июнь 3, 2024
Many
phenomena
in
nature
consist
of
multiple
elementary
processes.
If
we
can
predict
all
the
rate
constants
respective
processes
quantitatively,
comprehensively
and
understand
various
phenomena.
Here,
report
that
it
is
possible
to
quantitatively
related
quantum
yields
without
conducting
experiments,
using
multiple-resonance
thermally
activated
delayed
fluorescence
(MR-TADF)
as
an
example.
MR-TADFs
are
excellent
emitters
because
its
narrow
emission,
high
luminescence
efficiency,
chemical
stability,
but
they
have
one
drawback:
slow
reverse
intersystem
crossing
(RISC),
leading
efficiency
roll-off
reduced
device
lifetime.
show
a
calculation
method
for
obtaining
yields.
This
study
reveals
strategy
improve
RISC
compromising
other
important
factors:
radiative
decay
constants,
photoluminescence
yields,
emission
linewidths.
Our
be
applied
wide
range
research
fields,
providing
comprehensive
understanding
mechanism
including
time
evolution
excitons.