Advanced Functional Materials,
Год журнала:
2023,
Номер
34(12)
Опубликована: Дек. 8, 2023
Abstract
Halogenation
of
non‐fused
ring
electron
acceptors
(NFREAs)
plays
an
important
role
in
regulating
their
optoelectronic
properties.
However,
the
underlying
mechanisms
and
impact
on
performance
organic
solar
cells
(OSCs)
have
remained
unclear.
Herein,
a
series
halogenated
NFREAs
incorporating
F,
Cl,
Br,
are
prepared
to
study
effect
crystallization
kinetics,
phase
separation,
molecular
packing,
charge
transport.
Among
various
halogenation
strategies,
chlorination
minimizes
Coulomb
attractive
energy
between
donor
acceptor,
thereby
facilitating
exciton
dissociation.
In
situ
UV–vis
absorption
tests
reveal
that
chlorinated
exhibit
longer
time,
effectively
suppressing
excessive
aggregation
enhancing
overall
crystallinity.
Additionally,
diffusion
length,
which
promotes
dissociation
while
mitigating
recombination
devices.
Consequently,
two
NFREAs,
TCN‐Cl,
PCN‐Cl,
yield
impressive
power
conversion
efficiency
(PCE)
14.85%
15.30%,
respectively,
when
blended
with
PM6
J52
donors.
These
values
represent
highest
reported
PCEs
date
for
A‐π‐A’‐π‐A
A‐π‐D‐π‐A
structures.
The
elucidates
crucial
extending
length
time.
effects
significantly
benefit
separation
within
active
layers,
enhance
suppress
achieving
high‐efficiency
OSCs.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
64(1)
Опубликована: Авг. 24, 2024
Disordered
polymer
chain
entanglements
within
all-polymer
blends
limit
the
formation
of
optimal
donor-acceptor
phase
separation.
Therefore,
developing
effective
methods
to
regulate
morphology
evolution
is
crucial
for
achieving
morphological
features
in
organic
solar
cells
(APSCs).
In
this
study,
two
isomers,
4,5-difluorobenzo-c-1,2,5-thiadiazole
(SF-1)
and
5,6-difluorobenzo-c-1,2,5-thiadiazole
(SF-2),
were
designed
as
solid
additives
based
on
widely-used
electron-deficient
benzothiadiazole
unit
nonfullerene
acceptors.
The
incorporation
SF-1
or
SF-2
into
PM6
:
PY-DT
blend
induces
stronger
molecular
packing
via
interaction,
leading
continuous
interpenetrated
networks
with
suitable
phase-separation
vertical
distribution.
Furthermore,
after
treatment
SF-2,
exciton
diffusion
lengths
films
are
extended
over
40
nm,
favoring
charge
transport.
asymmetrical
characterized
by
an
enhanced
dipole
moment,
increases
power
conversion
efficiency
(PCE)
PY-DT-based
device
18.83
%
due
electrostatic
interactions.
Moreover,
a
ternary
strategy
boosts
PCE
SF-2-treated
APSC
19
%.
This
work
not
only
demonstrates
one
best
performances
APSCs
but
also
offers
approach
manipulate
using
rational-designed
additives.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
64(1)
Опубликована: Авг. 30, 2024
Strong
electron-phonon
coupling
can
hinder
exciton
transport
and
induce
undesirable
non-radiative
recombination,
resulting
in
a
shortened
diffusion
distance
constrained
dissociation
organic
solar
cells
(OSCs).
Therefore,
suppressing
is
crucially
important
for
achieveing
high-performance
OSCs.
Here,
we
employ
the
solid
additive
to
regulating
The
planar
configuration
of
SA1
confers
significant
advantage
lattice
vibrations
active
layers,
reducing
scattering
excitons
by
phonons.
Consequently,
slow
but
sustained
hole
transfer
process
identified
SA1-assisted
film,
indicating
an
enhancement
efficiency.
Prolonged
length
lifetime
are
achieved
blend
film
processed
with
SA1,
attributed
low
recombination
rate
energetic
disorder
charge
carrier
transport.
As
result,
high
efficiency
20
%
was
ternary
device
remarkable
short-circuit
current.
This
work
highlights
role
improving
photovoltaic
performance
Nature Communications,
Год журнала:
2025,
Номер
16(1)
Опубликована: Фев. 20, 2025
Abstract
Limited
by
large
batch
differences
and
inferior
polymerization
degree
of
current
polymer
acceptors,
the
potential
high
efficiency
stability
advantages
all-polymer
solar
cells
(all-PSCs)
cannot
be
fully
utilized.
Alternatively,
largely
π-extended
structurally
definite
oligomer
acceptors
are
effective
strategies
to
realize
overall
performance
acceptors.
Herein,
we
report
a
linear
tetramer
acceptor
namely
4Y-BO
with
identical
molecular
skeleton
comparable
molecular-weight
relative
control
PY-BO.
The
shows
refined
film-forming
kinetics
improved
ordering,
offering
uniform
crystallinity
donor
hence
well-defined
fibrous
heterojunction
textures.
Encouragingly,
PM6:4Y-BO
devices
achieve
an
up
19.75%
(certified
efficiency:19.58%),
surpassing
that
PM6:PY-BO
device
(15.66%)
ranks
highest
among
based
on
More
noticeably,
thermal
stability,
photostability
mechanical
flexibility
collectively
enhanced
for
devices.
Our
study
provides
important
approach
fabricating
stable
organic
photovoltaics.
Advanced Functional Materials,
Год журнала:
2023,
Номер
34(12)
Опубликована: Дек. 8, 2023
Abstract
Halogenation
of
non‐fused
ring
electron
acceptors
(NFREAs)
plays
an
important
role
in
regulating
their
optoelectronic
properties.
However,
the
underlying
mechanisms
and
impact
on
performance
organic
solar
cells
(OSCs)
have
remained
unclear.
Herein,
a
series
halogenated
NFREAs
incorporating
F,
Cl,
Br,
are
prepared
to
study
effect
crystallization
kinetics,
phase
separation,
molecular
packing,
charge
transport.
Among
various
halogenation
strategies,
chlorination
minimizes
Coulomb
attractive
energy
between
donor
acceptor,
thereby
facilitating
exciton
dissociation.
In
situ
UV–vis
absorption
tests
reveal
that
chlorinated
exhibit
longer
time,
effectively
suppressing
excessive
aggregation
enhancing
overall
crystallinity.
Additionally,
diffusion
length,
which
promotes
dissociation
while
mitigating
recombination
devices.
Consequently,
two
NFREAs,
TCN‐Cl,
PCN‐Cl,
yield
impressive
power
conversion
efficiency
(PCE)
14.85%
15.30%,
respectively,
when
blended
with
PM6
J52
donors.
These
values
represent
highest
reported
PCEs
date
for
A‐π‐A’‐π‐A
A‐π‐D‐π‐A
structures.
The
elucidates
crucial
extending
length
time.
effects
significantly
benefit
separation
within
active
layers,
enhance
suppress
achieving
high‐efficiency
OSCs.
