Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(16)
Published: Feb. 8, 2024
Multi-resonance
thermally
activated
delayed
fluorescence
(MR-TADF)
materials
hold
great
promise
for
advanced
high-resolution
organic
light-emitting
diode
(OLED)
displays.
However,
persistent
challenges,
such
as
severe
aggregation-caused
quenching
(ACQ)
and
slow
spin-flip,
hinder
their
optimal
performance.
We
propose
a
synergetic
steric-hindrance
excited-state
modulation
strategy
MR-TADF
emitters,
which
is
demonstrated
by
two
blue
IDAD-BNCz
TIDAD-BNCz,
bearing
sterically
demanding
8,8-diphenyl-8H-indolo[3,2,1-de]acridine
(IDAD)
3,6-di-tert-butyl-8,8-diphenyl-8H-indolo[3,2,1-de]acridine
(TIDAD),
respectively.
These
rigid
bulky
IDAD/TIDAD
moieties,
with
appropriate
electron-donating
capabilities,
not
only
effectively
mitigate
ACQ,
ensuring
efficient
luminescence
across
broad
range
of
dopant
concentrations,
but
also
induce
high-lying
charge-transfer
excited
states
that
facilitate
triplet-to-singlet
spin-flip
without
causing
undesired
emission
redshift
or
spectral
broadening.
Consequently,
implementation
high
doping
level
resulted
in
highly
narrowband
electroluminescence,
featuring
remarkable
full-width
at
half-maximum
34
nm
record-setting
external
quantum
efficiencies
34.3
%
31.8
maximum
100
cd
m
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(18)
Published: Feb. 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,
Journal Year:
2023,
Volume and Issue:
11(20), P. 6471 - 6511
Published: Jan. 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.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(27)
Published: April 29, 2023
Multi-resonance
thermally
activated
delayed
fluorescence
(MR-TADF)
materials
are
considered
a
class
of
organic
with
exceptional
electronic
and
optical
properties,
which
make
them
promising
for
the
applications
in
light-emitting
diodes
(OLEDs).
In
this
study,
we
improved,
synthesized,
characterized
multiple-resonance
type
emitter
based
on
assembly
MR-building
blocks
(MR-BBs).
By
optimizing
geometric
arrangement
MR-BBs,
were
able
to
generate
narrowband
emission
longer
wavelength
region
shorten
excited-state
lifetime,
resulting
improved
efficiency
compared
parent
molecule.
Our
proof-of-concept
molecule,
m-DBCz,
exhibited
yellowish-green
TADF
full
width
at
half-maximum
32
nm
small
singlet-triplet
energy
gap
0.04
eV.
The
OLED
developed
using
m-DBCz
as
demonstrated
electroluminescence
548
achieved
high
external
quantum
(EQE)
34.9
%.
Further
optimization
device
resulted
36.3
%
extremely
low
roll-off,
EQE
values
30.1
27.7
obtained
even
luminance
levels
50
000
100
cd
m-2
.
These
results
demonstrate
potential
MR-TADF
ultrahigh-luminance
OLEDs.
Materials Chemistry Frontiers,
Journal Year:
2024,
Volume and Issue:
8(7), P. 1731 - 1766
Published: Jan. 1, 2024
This
work
describes
recent
developments
in
near-infrared
(NIR)
organic
light-emitting
diode
(OLED)
emitters.
We
discuss
applications
of
NIR
OLEDs
as
well
various
groups
highly
luminescent
materials
used
the
OLED
emissive
layer.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(16)
Published: Feb. 8, 2024
Multi-resonance
thermally
activated
delayed
fluorescence
(MR-TADF)
materials
hold
great
promise
for
advanced
high-resolution
organic
light-emitting
diode
(OLED)
displays.
However,
persistent
challenges,
such
as
severe
aggregation-caused
quenching
(ACQ)
and
slow
spin-flip,
hinder
their
optimal
performance.
We
propose
a
synergetic
steric-hindrance
excited-state
modulation
strategy
MR-TADF
emitters,
which
is
demonstrated
by
two
blue
IDAD-BNCz
TIDAD-BNCz,
bearing
sterically
demanding
8,8-diphenyl-8H-indolo[3,2,1-de]acridine
(IDAD)
3,6-di-tert-butyl-8,8-diphenyl-8H-indolo[3,2,1-de]acridine
(TIDAD),
respectively.
These
rigid
bulky
IDAD/TIDAD
moieties,
with
appropriate
electron-donating
capabilities,
not
only
effectively
mitigate
ACQ,
ensuring
efficient
luminescence
across
broad
range
of
dopant
concentrations,
but
also
induce
high-lying
charge-transfer
excited
states
that
facilitate
triplet-to-singlet
spin-flip
without
causing
undesired
emission
redshift
or
spectral
broadening.
Consequently,
implementation
high
doping
level
resulted
in
highly
narrowband
electroluminescence,
featuring
remarkable
full-width
at
half-maximum
34
nm
record-setting
external
quantum
efficiencies
34.3
%
31.8
maximum
100
cd
m
