Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Dec. 3, 2024
Abstract
Achieving
high
efficiency
narrowband
near‐ultraviolet
(NUV)
emitters
in
organic
light
emitting
diode
(OLED)
is
still
a
formidable
challenge.
Herein,
proof‐of‐concept
hybridized
local
and
charge
transfer
(HLCT)
molecule,
named
ICz‐BO,
prepared
characterized,
which
both
multiresonant
(MR)
skeletons
are
integrated
via
conjugation
connection.
A
slightly
distorted
structure
weak
intramolecular
(CT)
interaction
between
two
MR
subunits
lead
to
high‐lying
reverse
intersystem
crossing
(h‐RISC)
channel
of
T
6
→
S
1
,
also
evidenced
by
experimental
calculated
results.
Impressively,
the
ICz‐BO
emitter
exhibits
outstanding
NUV
emission
at
404
nm
with
full‐width
half
maximum
28
toluene
solution.
The
solution
processable
OLED
shows
an
excellent
device
performance
recorded
external
quantum
12.01
%,
concomitant
extremely
low
y‐axis
Commission
Internationale
de
l’Éclairage
(CIE
y
)
value
0.031.
To
best
our
knowledge,
this
highest
reported
for
HLCT‐based
NUV‐OLEDs
date.
This
research
proves
that
skeleton
plays
positive
effect
on
hot
exciton
emitter,
provides
alternative
paradigm
developing
high‐efficiency
emitters.
Advanced Materials,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 11, 2025
Abstract
The
hyperfluorescence
(HF)
technology
holds
great
promise
for
the
development
of
high‐quality
organic
light‐emitting
diodes
(OLEDs)
their
excellent
color
purity,
high
efficiency,
and
low‐efficiency
roll‐off.
Sensitizer
plays
a
crucial
role
in
performance
HF
devices.
However,
designing
sensitizers
with
simultaneous
photoluminescence
quantum
yield
(PLQY),
rapid
radiative
decay
(
k
r
),
fast
reverse
intersystem
crossing
rate
RISC
)
poses
challenge,
particularly
thermally
activated
delayed
fluorescence
(TADF)
targeting
deep‐blue
device.
Herein,
by
introducing
boron‐containing
multi‐resonance‐type
acceptor
into
multi‐
tert
‐butyl‐carbazole
encapsulated
benzene
molecular
skeleton,
two
TADF
emitters
featuring
hybridized
multi‐channel
charge‐transfer
pathways,
including
short‐range
multi‐resonance,
weakened
through‐bond,
compact
face‐to‐face
through‐space
charge‐transfer.
Benefiting
from
rational
design,
proof‐of‐concept
exhibit
5.3
×
10
7
s
−1
,
up
to
5.9
5
PQLY
near‐unity,
as
well
ideal
emission
both
solution
film.
Consequently,
corresponding
devices
not
only
achieve
chromaticity
coordinates
that
fully
comply
latest
BT.
2020
standards,
but
also
showcase
record‐high
maximum
external
efficiencies
nearing
40%,
along
suppressed
efficiency
Advanced Materials,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Oct. 15, 2024
Compared
with
the
classical
boron/nitrogen
(B/N)
doped
ones,
multiple-resonance
thermally
activated
delayed
fluorescence
(MR-TADF)
emitters
embedded
B-N
covalent
bond
behave
a
significantly
blue-shifted
narrowband
TADF,
and
thus
show
greater
potential
in
ultrapure
blue
organic
light-emitting
diodes
(OLEDs).
As
proof
of
concept,
herein
peripheral
substitution
engineering
is
demonstrated
based
on
such
B‒N
parent
core.
The
simple
approach
found
to
ensure
easy
synthesis
via
one-pot
lithium-free
borylation-annulation,
manipulate
excited
states
through
different
electronic
coupling
between
core
substituent,
introduce
steric
hindrance
minimize
unwanted
spectral
broadening.
Impressively,
OLEDs
are
realized
give
high
external
quantum
efficiency
20.3%
together
Commission
Internationale
de
l'Éclairage
coordinates
(0.152,
0.046).
performance
well
competent
those
B/N
MR-TADF
emitters,
clearly
highlighting
that
framework
novel
promising
paradigm
towards
efficient
BT.2020
standard.
Advanced Functional Materials,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Sept. 9, 2024
Abstract
Developing
narrowband
blue
multiple
resonance
(MR)
organic
emitters
with
Commission
Internationale
de
L'Eclairage
(CIE)
y
coordinates
<0.1
is
essential
for
advanced
display
technologies.
This
study
proposes
a
deep‐blue
thermally
activated
delayed
fluorescence
(TADF)
emitter,
named
2BNO,
which
integrates
two
independent
MR
cores.
Unlike
many
TADF
materials
single‐bonded
dual
emitting
cores,
2BNO
utilizes
steric
hindrance‐assisted
fluorene
bridge
to
achieve
an
orthorhombic
molecular
structure.
The
dual‐core
MR‐TADF
emitter
shows
enhanced
light
absorption
and
high
photoluminescence
quantum
yield.
Notably,
the
emission
of
not
significantly
redshifted
compared
single‐core
compounds
maintains
narrow
full
width
at
half‐maximum
(FWHM)
24
nm
CIE
(0.147,
0.041)
in
2Me‐THF
solution,
nearing
BT.2020
standard.
Organic
light‐emitting
diodes
(OLEDs)
incorporating
as
exhibit
460
FWHM
29
(0.14,
0.09).
core
design
improves
device
efficiency,
achieving
external
efficiency
(EQE)
19.8%.
strategy
this
work
demonstrated
be
effective
promoting
while
preserving
color
purity.
Advanced Materials,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Oct. 12, 2024
Abstract
Here
the
utility
and
potential
of
an
emitter
design
are
demonstrated,
consisting
a
narrowband‐emitting
multiresonant
thermally
activated
delayed
fluorescent
(MR‐TADF)
core
that
is
decorated
with
suitably
higher
energy
donor‐acceptor
TADF
moiety.
Not
only
does
this
D–A
group
offer
additional
channels
for
triplet
exciton
harvesting
confers
faster
reverse
intersystem
crossing
(RISC)
kinetics
but
it
also
acts
as
steric
shield,
insulating
emissive
MR‐TADF
from
aggregation‐caused
quenching.
Two
emitters,
DtCzBN‐CNBT1
DtCzBN‐CNBT2
,
demonstrate
enhanced
photophysical
properties
leading
to
outstanding
performance
organic
light‐emitting
diodes
(OLEDs).
containing
moiety,
has
k
RISC
(1.1
×
10
5
s
−1
)
photoluminescence
quantum
yield
(
Φ
PL
:
97%)
compared
(0.2
90%),
which
contains
moiety
itself
not
TADF.
The
sensitizer‐free
OLEDs
achieve
record‐high
maximum
external
efficiency
(EQE
max
40.2%
showed
milder
roll‐off
1000
20.7%)
‐based
devices
37.1%
EQE
11.9%).
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(47), P. 32826 - 32836
Published: Nov. 13, 2024
Advanced
multiresonance-induced
thermally
activated
delayed
fluorescence
(MR-TADF)
materials
exhibit
exceptional
promise
for
applications
in
state-of-the-art
organic
light-emitting
diodes
(OLEDs)
owing
to
their
unique
narrowband
emissions
and
high
luminescent
efficiencies.
Despite
substantial
progress
with
blue
green
MR-TADF
materials,
the
development
of
pure-red
emitters
has
lagged
behind,
thereby
hindering
advancement
toward
high-performance
ultrahigh-definition
OLED
displays.
Here,
we
propose
an
effective
approach
designing
molecules
based
on
integration
secondary
electron-donating
units
π-skeleton
extension
into
MR
cores,
which
enables
not
only
a
redshift
emission
but
also
acceleration
reverse
intersystem
crossing
(RISC)
rate.
The
proof-of-the-concept
emitter
BNTPA
showcases
bright
saturated
red
centered
at
613
nm
full-width
half-maximum
0.14
eV,
together
more
than
twofold
increase
RISC
As
result,
TADF
OLEDs
achieved
record
maximum
external
quantum
efficiency
(EQ
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Dec. 3, 2024
Abstract
Achieving
high
efficiency
narrowband
near‐ultraviolet
(NUV)
emitters
in
organic
light
emitting
diode
(OLED)
is
still
a
formidable
challenge.
Herein,
proof‐of‐concept
hybridized
local
and
charge
transfer
(HLCT)
molecule,
named
ICz‐BO,
prepared
characterized,
which
both
multiresonant
(MR)
skeletons
are
integrated
via
conjugation
connection.
A
slightly
distorted
structure
weak
intramolecular
(CT)
interaction
between
two
MR
subunits
lead
to
high‐lying
reverse
intersystem
crossing
(h‐RISC)
channel
of
T
6
→
S
1
,
also
evidenced
by
experimental
calculated
results.
Impressively,
the
ICz‐BO
emitter
exhibits
outstanding
NUV
emission
at
404
nm
with
full‐width
half
maximum
28
toluene
solution.
The
solution
processable
OLED
shows
an
excellent
device
performance
recorded
external
quantum
12.01
%,
concomitant
extremely
low
y‐axis
Commission
Internationale
de
l’Éclairage
(CIE
y
)
value
0.031.
To
best
our
knowledge,
this
highest
reported
for
HLCT‐based
NUV‐OLEDs
date.
This
research
proves
that
skeleton
plays
positive
effect
on
hot
exciton
emitter,
provides
alternative
paradigm
developing
high‐efficiency
emitters.
Advanced Functional Materials,
Journal Year:
2025,
Volume and Issue:
unknown
Published: April 18, 2025
Abstract
Organic
fluorophores
with
through‐space
donor/acceptor
interaction
have
garnered
significant
attention
for
their
unique
charge
transfer
properties
and
advanced
applications.
However,
use
in
luminescent
applications
is
hindered
by
challenges
such
as
low
luminescence
efficiency,
broad
emission
spectra.
Herein,
a
series
of
highly
emissive
thermally
activated
delayed
combining
boron‐based
multi‐resonance
acceptor
an
arylamine
donor
within
spatially
compacted
structure
designed
synthesized.
By
strategically
varying
spatial
compactness,
interactions
are
fine‐tuned,
enabling
precise
control
over
high‐lying
excited
states
characteristics
while
preserving
narrow‐spectrum
fluorescence.
Key
structural
optimizations,
including
planar
space‐compacting
methyl
group,
resulted
compact
configuration,
boosting
reverse
intersystem
crossing
rates
20‐fold
compared
to
the
parent
fluorophore.
This
design
minimizes
concentration‐induced
quenching
spectral
broadening,
yielding
superior
solid‐state
luminescence.
The
resulting
organic
light‐emitting
diodes
achieved
ultranarrow
electroluminescence
(full
width
at
half‐maximum
22
nm)
remarkable
external
quantum
efficiency
31.1%,
along
reduced
roll‐offs.
Chemical Reviews,
Journal Year:
2025,
Volume and Issue:
unknown
Published: May 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.
