Angewandte Chemie,
Год журнала:
2024,
Номер
136(38)
Опубликована: Июль 6, 2024
Abstract
Herein,
we
propose
a
regional
functionalization
molecular
design
strategy
that
enables
independent
control
of
distinct
pivotal
parameters
through
different
molecule
segments.
Three
novel
multiple
resonances
thermally
activated
delayed
fluorescence
(MR‐TADF)
emitters
A‐BN,
DA‐BN,
and
A‐DBN,
have
been
successfully
synthesized
by
integrating
highly
rigid
three‐dimensional
adamantane‐containing
spirofluorene
units
into
the
MR
framework.
These
molecules
form
two
distinctive
functional
parts:
part
1
comprises
boron‐nitrogen
(BN)‐MR
framework
with
adjacent
benzene
fluorene
forming
central
luminescent
core
characterized
an
exceptionally
planar
geometry,
allowing
for
narrow
FWHM
values;
2
includes
peripheral
mesitylene,
benzene,
adamantyl
groups,
creating
unique
“umbrella‐like”
conformation
to
mitigate
intermolecular
interactions
suppress
exciton
annihilation.
The
resulting
A‐DBN
exhibit
remarkably
values
ranging
from
18
14
nm
near‐unity
photoluminescence
quantum
yields.
Particularly,
OLEDs
based
on
DA‐BN
demonstrate
outstanding
efficiencies
35.0
%
34.3
%,
as
low
22
25
nm,
respectively,
effectively
accomplishing
integration
high
color
purity
device
performance.
Advanced Materials,
Год журнала:
2024,
Номер
36(19)
Опубликована: Фев. 7, 2024
Exciplex
systems
are
promising
candidates
for
thermally
activated
delayed
fluorescence
(TADF)
molecules
because
of
the
small
energy
difference
between
lowest
singlet
and
triplet
excited
states
(ΔE
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Июль 22, 2024
Abstract
Multi-resonance
thermally
activated
delayed
fluorophores
have
been
actively
studied
for
high-resolution
photonic
applications
due
to
their
exceptional
color
purity.
However,
these
compounds
encounter
challenges
associated
with
the
inefficient
spin-flip
process,
compromising
device
performance.
Herein,
we
report
two
pure-blue
emitters
based
on
an
organoboron
multi-resonance
core,
incorporating
a
conformationally
flexible
donor,
10-phenyl-5
H
-phenophosphazinine
10-oxide
(or
sulfide).
This
design
concept
selectively
modifies
orbital
type
of
high-lying
excited
states
charge
transfer
configuration
while
simultaneously
providing
necessary
conformational
freedom
enhance
density
without
sacrificing
We
show
that
different
embedded
phosphorus
motifs
(phosphine
oxide/sulfide)
donor
can
finely
tune
electronic
structure
and
freedom,
resulting
in
accelerated
process
through
intense
spin-vibronic
coupling,
achieving
over
20-fold
increase
reverse
intersystem
crossing
rate
compared
parent
emitter.
Utilizing
emitters,
achieve
high-performance
organic
light-emitting
diodes,
showcasing
top-tier
external
quantum
efficiency
37.6%
reduced
roll-offs.
proposed
strategy
not
only
conventional
notion
electron-donors
are
undesirable
constructing
narrowband
but
also
offer
pathway
designing
efficient
narrow-spectrum
blue
diodes.
Advanced Materials,
Год журнала:
2024,
Номер
36(30)
Опубликована: Май 2, 2024
Abstract
Ultrapure
deep‐blue
emitters
are
in
high
demand
for
organic
light‐emitting
diodes
(OLEDs).
Although
color
coordinates
serve
as
straightforward
parameters
assessing
purity,
precise
control
over
the
maximum
wavelength
and
full‐width
at
half‐maximum
is
necessary
to
optimize
OLED
performance,
including
luminance
efficiency
luminous
efficacy.
Multiple‐resonance
(MR)
promising
candidates
achieving
ideal
luminescence
properties;
consequently,
a
wide
variety
of
MR
frameworks
have
been
developed.
However,
most
these
experience
displacement
from
color,
which
limits
their
practical
applicability.
Therefore,
molecular
design
that
compatible
with
modulating
energy
levels
output
particularly
valuable.
Here,
it
demonstrated
azepine
donor
unit
induces
an
appropriate
blue‐shift
emission
while
maintaining
efficient
characteristics,
photoluminescence
quantum
yield,
narrow
emission,
fast
reverse
intersystem
crossing
rate.
OLEDs
using
newly
developed
based
on
ν
‐DABNA
framework
simultaneously
exhibit
≈30%,
efficacy
≈20
lm
W
−1
,
exceptional
purity
Commission
Internationale
de
l’Éclairage
low
(0.14,
0.06),
notably
operational
stability.
These
results
demonstrate
unprecedentedly
compared
those
observed
previously
reported
emitters.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(38)
Опубликована: Июль 6, 2024
Herein,
we
propose
a
regional
functionalization
molecular
design
strategy
that
enables
independent
control
of
distinct
pivotal
parameters
through
different
molecule
segments.
Three
novel
multiple
resonances
thermally
activated
delayed
fluorescence
(MR-TADF)
emitters
A-BN,
DA-BN,
and
A-DBN,
have
been
successfully
synthesized
by
integrating
highly
rigid
three-dimensional
adamantane-containing
spirofluorene
units
into
the
MR
framework.
These
molecules
form
two
distinctive
functional
parts:
part
1
comprises
boron-nitrogen
(BN)-MR
framework
with
adjacent
benzene
fluorene
forming
central
luminescent
core
characterized
an
exceptionally
planar
geometry,
allowing
for
narrow
FWHM
values;
2
includes
peripheral
mesitylene,
benzene,
adamantyl
groups,
creating
unique
"umbrella-like"
conformation
to
mitigate
intermolecular
interactions
suppress
exciton
annihilation.
The
resulting
A-DBN
exhibit
remarkably
values
ranging
from
18
14
nm
near-unity
photoluminescence
quantum
yields.
Particularly,
OLEDs
based
on
DA-BN
demonstrate
outstanding
efficiencies
35.0
%
34.3
%,
as
low
22
25
nm,
respectively,
effectively
accomplishing
integration
high
color
purity
device
performance.
Advanced Optical Materials,
Год журнала:
2024,
Номер
12(21)
Опубликована: Апрель 9, 2024
Abstract
While
the
development
of
solution‐processed
organic
light‐emitting
diodes
(sOLEDs)
utilizing
multiple
resonance‐induced
thermally
activated
delayed
fluorescence
(MR‐TADF)
is
highly
significant,
it
restricted
by
limited
solubility
and
film‐forming
property
resulting
from
rigid
conjugate
planarity
MR‐TADF
materials.
Herein,
an
effective
strategy
presented
to
obtain
narrowband
emitters
introducing
inert
steric
bulky
hindrance
group
into
resonance
skeleton,
thereby
mitigating
issues
arising
intermolecular
packing‐induced
poor
solution
processing
ability
quenching
effects.
The
target
emitter,
designed
as
3CzSF‐BN,
exhibits
pure‐green
emission
with
a
peak
at
520
nm
small
full
width
half
maximum
(FWHM)
30
(0.14)
eV.
Remarkably,
achieves
exceptional
photoluminescence
quantum
yield
(PLQY)
100%
notable
advancements
in
attributes.
optimized
bottom‐emitting
sOLED
(BE‐sOLED)
device
external
efficiency
(EQE)
over
20%
Commission
Internationale
de
I’Éclairage
(CIE)
coordinates
(0.214,
0.716).
Notably,
top‐emitting
(TE‐sOLED)
ultra‐pure
green
color
FWHM
22
CIE
(0.138,
0.771),
highlighting
effectiveness
this
designing
high‐performance
Advanced Materials,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 23, 2025
Abstract
Herein,
a
parallel
“bifunctional
group”
modulation
method
is
proposed
to
achieve
controlled
of
the
emission
wavelength
and
full‐width
at
half‐maximum
(FWHM)
values.
As
result,
three
proof‐of‐concept
emitters,
namely
DBNDS‐TPh,
DBNDS‐DFPh,
DBNDS‐CNPh,
are
designed
synthesized,
with
first
functional
dibenzo[
b,d
]thiophene
unit
concurrently
reducing
bandgap
elevate
their
triplet
state
energy.
A
second
group
1
,
′:
3
′,
″‐
triphenyl
electron
acceptors
1,3‐difluorobenzene
benzonitrile
respectively,
deepen
HOMO
LUMO
levels.
Accordingly,
CIE
coordinates
DBNDS‐CNPh
(0.13,
0.77),
(0.14,
0.76)
in
dilute
toluene
solution.
This
marks
instance
achieving
y
value
0.77
solutions.
Significantly,
non‐sensitized
pure‐green
OLEDs
based
on
DBNDS‐TPh
DBNDS‐DFPh
demonstrate
peak
EQE
35.0%
34.5%,
corresponding
(0.18,
0.75),
(0.17,
doping
concentration
wt.%,
representing
green
OLED
reaching
0.76
bottom‐emitting
device
structure
as
reported
literature.
Advanced Optical Materials,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 8, 2025
Abstract
Organic
light‐emitting
diodes
(OLEDs)
exhibit
significant
advantages
in
the
fields
of
ultra‐high‐definition
(UHD)
displays
and
wearable
devices.
However,
developing
low‐cost,
high‐efficiency,
high‐purity
blue
emission
materials
remains
a
challenge
for
academia
industry.
While
thermally
activated
delayed
fluorescence
(TADF)
meet
low‐cost
manufacturing
needs
achieve
100%
internal
quantum
efficiency,
their
charge‐transfer
excited
states
lead
to
broad
spectra
that
don't
BT.2020
standard.
Fortunately,
multiple
resonance
(MR)
strategy
offers
an
effective
solution
creating
TADF
with
high
color
purity.
Through
careful
structural
design
precise
tuning
state
energy
levels,
MR‐TADF
can
easily
full‐width
at
half‐maximum
(FWHM)
less
than
30
nm.
Nevertheless,
it
still
faces
challenges,
such
as
severe
aggregation‐induced
quenching
efficiency
roll‐off.
Herein,
this
work
overviews
recent
progress
devices,
introduce
representative
molecular
strategies
aimed
suppressing
concentration
quenching,
enhancing
reverse
intersystem
crossing
rates,
achieving
deep
emission,
which
will
aid
future
endeavors
develop
more
efficient,
stable
devices
suitable
UHD
display
applications.
