Advanced Optical Materials,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 25, 2024
Abstract
Multiple‐resonance
(MR)
type
emitters
have
overcome
several
issues
in
organic
light‐emitting
diodes
(OLEDs)
because
of
their
narrowband
emission
and
high
electroluminescence
quantum
yield
efficiency.
Also,
this
kind
has
been
widely
used
as
hyperfluorescence
(HF)‐OLEDs
thanks
to
advantageous
properties.
However,
there
a
significant
challenge
for
HF‐OLEDs
based
on
MR
emitters,
which
is
impacted
by
the
nature
long‐lived
triplet
excitons
trade‐off
between
short
exciton
lifetime.
Herein,
low‐possessed
energy
level
pyrene
introduced
an
core
unit
achieve
stable
with
development
three
isomers
investigate
regioisomer
effect
pyrenes.
The
improved
device
lifetimes
are
successfully
achieved,
reasons
differences
excimer
formation
stability
those
studied.
Advanced Materials,
Год журнала:
2024,
Номер
unknown
Опубликована: Окт. 18, 2024
Organic
room-temperature
phosphorescent
(RTP)
materials,
especially
with
narrowband
emission
properties,
exhibit
great
potential
for
applications
in
display
and
sensing,
but
have
been
seldom
reported.
Herein,
a
rare
example
of
the
intrinsic
blue
RTP
material
is
fabricated
A
series
indolo[3,2,1-kl]phenothiazine
derivatives,
named
Cphpz,
1O-Cphpz,
2O-Cphpz,
are
designed
synthesized.
Due
to
their
relatively
rigid
structures,
these
three
compounds
showed
deep
emissions
ranging
from
396
434
nm
full
width
at
half
maximum
(FWHM)
31,
26,
31
nm,
respectively.
To
delight,
compound
2O-Cphpz
displayed
448
FWHM
36
long-lived
lifetime
1.08
s
hydroxyethyl
acrylate
acrylic
acid
matrix.
Photophysical
studies,
single
crystal
analyses,
TD-DFT
calculations
performed
elucidate
further
relationships
between
molecular
structures
properties.
Meanwhile,
because
highly
sensitive
humidity,
visualizing
droplet
path
optical
microfluidic
chip
efficiently
through
digital
light
processing
3D
printing.This
work
provides
reliable
strategy
realize
expand
self-monitoring
printed
structures.
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.
The Journal of Physical Chemistry A,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 6, 2025
Multiple-resonance
thermally
activated
delayed
fluorescence
(MR-TADF)
materials
have
attracted
extensive
attention
due
to
their
100%
exciton
utilization
efficiency
and
narrowband
emissions.
Numerous
tube-shaped
MR-TADF
emitters
with
full-color
emissions
been
reported,
updated
molecular
design
strategies
need
be
proposed
find
more
"recipes"
narrow
the
emission
spectral
range.
Upon
changing
shape
of
fluorophore
from
a
tubular
fan-shaped
structure,
investigated
molecules
exhibit
based
on
analysis
geometric
electronic
structures,
reorganization
energies,
charge
transfer
characters
upon
excitation,
absorption
properties.
The
small
energies
short-range
properties
excitation
are
key
narrowing
range
molecules.
Such
theoretical
investigations
give
an
in-depth
insight
into
structure-property
relationship,
would
provide
important
guidance
for
multiple-resonance
The Journal of Physical Chemistry A,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 26, 2025
Nitrogen
substitutions
have
shown
a
great
impact
for
the
development
of
thermally
activated
delayed
fluorescence
(TADF)-based
organic
light-emitting
diode
(OLED)
materials.
In
particular,
much
focus
has
been
devoted
to
nitrogen-substituted
polycyclic
aromatic
hydrocarbons
(PAHs)
TADF
emitters.
this
context,
we
provide
here
molecular
design
approach
symmetric
nitrogen
in
fused
benzene
ring
PAHs
based
on
dibenzo[a,c]picene
(DBP)
molecule.
We
designed
possible
donor–acceptor
(D–A)
compounds
with
dimethylcarbazole
(DMCz)
and
dimethyldiphenylamine
(DMDPA)
donors
studied
structure
photophysics
D–A
compounds.
The
twisted
extended
D–A-type
PAH
emitters
demonstrate
red
near-infrared
(NIR)
emission.
lead
significant
LUMO
stabilization
reduced
HOMO–LUMO
energy
gaps
as
well.
Additionally,
computed
significantly
smaller
singlet–triplet
splittings
(ΔEST)
comparison
non-nitrogen-substituted
investigated
ortho-linked
show
relatively
large
twisting
separation
small
ΔEST
compared
their
para-linked
counterparts.
For
higher
number
(4N)-substituted
emitters,
predict
adiabatic
(ΔESTadia)
range
0.01–0.13
eV,
tert-butylated
donors,
even
obtained
ΔESTadia
values
0.007
eV.
Computed
spin–orbit
coupling
(SOC)
T1
triplet
state
order
0.12–2.28
cm–1
suggests
repopulation
singlet
charge
transfer
(1CT)
excitons
from
CT
locally
excited
(3CT+LE)
states.
Importantly,
SOC
induce
reverse
intersystem
crossing
(RISC)
rate
high
1
×
106
s–1,
which
will
cause
NIR
4N-substituted
Notably,
emission
compound
B4
at
670
nm
D4
713
987
1217
D3
E3,
respectively.
