The Journal of Physical Chemistry Letters,
Год журнала:
2024,
Номер
unknown, С. 340 - 348
Опубликована: Дек. 27, 2024
Circularly
polarized
multiple-resonance
thermally
activated
delayed
fluorescence
(CP-MR-TADF)
materials
have
received
widespread
attention
in
recent
years,
but
it
remains
a
formidable
challenge
to
design
high-performance
CP-MR-TADF
emitters
concurrently
exhibiting
high
quantum
efficiency,
narrowband
emission,
and
dissymmetry
factor
(g).
Here,
we
perform
an
in-depth
theoretical
investigation
on
the
based
[2.2]
paracyclophane
(pCp)
derivatives.
The
MR-based
with
enhanced
long-range
charge
transfer
(LRCT)
characteristics
upon
excitation
show
increased
g
values
owing
coaxial
dominated
transition
components
of
electric
dipole
moment
(TEDM)
magnetic
(TMDM)
inevitably
result
loss
emission
performance.
Furthermore,
newly
designed
molecules
by
fusing
peripheral
benzene
units
MR
cores
within
planar
chiral
pCp
bridge
maintain
emissions
exhibit
order
1
×
10–3.
These
findings
rich
physical
insights
structure–performance
relation
paracyclophane-based
should
provide
important
clues
for
designing
materials.
Advanced Optical Materials,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 21, 2025
Abstract
The
preparation
of
narrow
emission
bandwidth
materials
is
crucial
for
the
development
advanced
organic
light‐emitting
diodes
(OLEDs).
In
this
review
article,
state‐of‐the‐art
methodologies
used
emitters
with
high
color
purity
are
summarized,
and
favorable
design
strategies
rationally
organized.
Currently
OLEDs
have
some
issues,
such
as
device
stabilization
that
must
be
resolved,
should
also
considered.
Given
recent
exponential
growth
in
number
types
narrowband
emissive
organometallic
complexes
exhibiting
multiple‐resonance
thermally
activated
delayed
fluorescence
metal‐to‐ligand
charge
transfer
characteristics,
there
an
urgent
need
to
establish
key
technology
descriptors
purity.
review,
developments
boron,
fused
indolocarbazole,
carbonyl,
phosphine
oxide,
exhibit
spectra
described,
future
directions
advance
performance
devices
suggested.
Chemical Science,
Год журнала:
2024,
Номер
15(29), С. 11435 - 11443
Опубликована: Янв. 1, 2024
A
multi-resonance
thermally
activated
delayed
fluorescence
emitter
with
five-membered
thiophene
as
the
π-core
is
first
developed.
The
corresponding
OLEDs
exhibit
high
efficiency,
narrowband
emission
and
reduced
efficiency
roll-off
simultaneously.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 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 Optical Materials,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 5, 2025
Abstract
Introducing
heavy
atoms
to
enhance
spin‐orbit
coupling
represents
an
effective
strategy
for
boosting
the
reverse
intersystem
crossing
(RISC)
rate
constants
of
Multi‐resonance
thermally
activated
delayed
fluorescence
(MR‐TADF)
emitters.
Nevertheless,
restricted
diversity
molecular
structures
obstructs
a
thorough
investigation
structure‐property
relationships,
thereby
limiting
improvement
device
performance,
especially
in
case
solution‐processed
devices.
Herein,
alkylthio‐substituted
carbazole
building
block
is
designed
and
developed
two
new
MR‐TADF
emitters,
namely
BNCz‐2S
BNCz‐4S.
Quantum
simulations
photophysical
studies
have
revealed
that
as
number
sulfur
increases,
BNCz‐4S
exhibits
higher
photoluminescence
quantum
yield
(PLQY),
smaller
singlet‐triplet
energy
gap
(Δ
E
ST
)
reorganization
energy,
along
with
larger
(SOC)
constant
(
k
RISC
compared
BNCz‐2S.
Consequently,
solution‐processing
devices
based
on
exhibit
external
efficiency
(EQE)
24.06%,
which
first
tier
reported
organic
light‐emitting
diodes
(OLED)
date.
ACS Applied Materials & Interfaces,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 26, 2025
Multiple
resonance
(MR)
thermally
activated
delayed
fluorescence
(TADF)
materials
hold
significant
potential
for
applications
in
high
color
purity
and
highly
efficient
organic
light-emitting
diodes
(OLEDs).
However,
their
inherently
large
planar
structures
often
result
severe
aggregation-induced
quenching
slow
spin-flip
processes,
presenting
challenges
that
limit
practical
applications.
In
this
study,
we
designed
synthesized
two
MR-TADF
molecules,
tCON-Cz
tCON-2tBuCz,
by
incorporating
a
tCON
backbone
with
carbazole
or
3,6-di-tert-butylcarbazole
at
the
ortho
position
of
phenyl
ring.
This
strategic
design
introduces
twisted
three-dimensional
structure,
effectively
mitigating
quenching.
Additionally,
it
creates
through-space
charge
transfer
channel
facilitates
reverse
intersystem
crossing,
thereby
enhancing
TADF
efficiency.
As
result,
both
molecules
exhibit
photoluminescence
quantum
yields.
When
incorporated
into
devices,
these
OLEDs
demonstrated
remarkable
performance,
achieving
external
efficiencies
23.70%
22.84%
tCON-2tBuCz
doping
concentrations
as
20%.
Notably,
devices
retained
narrow
full
width
half-maximum
around
36
nm,
consistent
parent
skeleton,
ensuring
superior
purity.
Advanced Materials,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 27, 2025
Abstract
Achieving
both
high‐efficiency
and
narrowband
emission
in
thermally
activated
delayed
fluorescence
(TADF)
polymers
remains
a
formidable
challenge.
In
this
work,
proof
of
concept
for
narrowband‐emissive
TADF
with
partially
conjugated
structure
is
proposed
by
embedding
silicon─carbon
σ‐bond
saturated
spacer
between
the
multiresonance
(MR)
unit
polycarbazole
backbone.
A
series
PSix
(
x
=
1,
3,
6)
then
prepared
characterized.
All
show
full
width
at
half
maximum
(FWHM)
values
28–30
nm
toluene
solution.
Impressively,
polymer
PSi3
has
highest
photoluminescence
quantum
yield,
reaching
97%,
doped
films
due
to
efficient
reverse
intersystem
crossing
process.
The
solution‐processed
devices
based
on
exhibit
best
performance
external
efficiency
EQE
max
)
28.8%
an
FWHM
42
nm.
By
employing
molecule
5Cz‐TRZ
as
sensitizer,
enhanced
device
30.2%
achieved,
which
first
tier
among
MR‐TADF
reported
date.
This
work
provides
effective
strategy
achieving
highly
controlling
chromophore
Advanced Optical Materials,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 11, 2025
Abstract
Luminescent
boron‐nitrogen
(BN)‐type
multi‐resonance
(MR)
materials
have
been
first
reported
by
Hatakeyama
and
co‐workers
in
2016.
BN‐type
MR
attracted
a
lot
of
attention,
because
their
unique
photophysical
properties,
including
narrowband
emissions,
high
photoluminescent
quantum
yields,
thermally
activated
delayed
fluorescent
(TADF)
properties.
MR‐TADF
are
considered
as
the
next‐generation
luminescent
for
efficient,
stable,
narrow‐emission
organic
light‐emitting
diodes
(OLEDs).
Herein,
comprehensive
review
recent
progress
is
provided
highlighting
structures,
device
performances.
Moreover,
future
perspective
development
will
be
discussed.
