Advanced Materials,
Journal Year:
2023,
Volume and Issue:
35(35)
Published: May 19, 2023
Abstract
Organic
solar
cells
benefit
from
non‐fullerene
acceptors
(NFA)
due
to
their
high
absorption
coefficients,
tunable
frontier
energy
levels,
and
optical
gaps,
as
well
relatively
luminescence
quantum
efficiencies
compared
fullerenes.
Those
merits
result
in
yields
of
charge
generation
at
a
low
or
negligible
energetic
offset
the
donor/NFA
heterojunction,
with
over
19%
achieved
for
single‐junction
devices.
Pushing
this
value
significantly
20%
requires
an
increase
open‐circuit
voltage,
which
is
currently
still
below
thermodynamic
limit.
This
can
only
be
by
reducing
non‐radiative
recombination,
hereby
increasing
electroluminescence
efficiency
photo‐active
layer.
Here,
current
understanding
origin
decay,
accurate
quantification
associated
voltage
losses
are
summarized.
Promising
strategies
suppressing
these
highlighted,
focus
on
new
material
design,
optimization
donor–acceptor
combination,
blend
morphology.
review
aims
guiding
researchers
quest
find
future
harvesting
blends,
combine
yield
exciton
dissociation
radiative
free
carrier
recombination
losses,
closing
gap
inorganic
perovskite
photovoltaics.
Chemical Reviews,
Journal Year:
2022,
Volume and Issue:
122(18), P. 14180 - 14274
Published: Aug. 5, 2022
Organic
photovoltaics
(OPVs)
have
progressed
steadily
through
three
stages
of
photoactive
materials
development:
(i)
use
poly(3-hexylthiophene)
and
fullerene-based
acceptors
(FAs)
for
optimizing
bulk
heterojunctions;
(ii)
development
new
donors
to
better
match
with
FAs;
(iii)
non-fullerene
(NFAs).
The
application
NFAs
an
A–D–A
configuration
(where
A
=
acceptor
D
donor)
has
enabled
devices
efficient
charge
generation
small
energy
losses
(Eloss
<
0.6
eV),
resulting
in
substantially
higher
power
conversion
efficiencies
(PCEs)
than
FA-based
devices.
discovery
Y6-type
(Y6
2,2′-((2Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]-thiadiazolo[3,4-e]-thieno[2″,3″:4′,5′]thieno-[2′,3′:4,5]pyrrolo-[3,2-g]thieno-[2′,3′:4,5]thieno-[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile)
A–DA′
D–A
further
propelled
the
PCEs
go
beyond
15%
due
smaller
Eloss
values
(∼0.5
eV)
external
quantum
efficiencies.
Subsequently,
Y6-series
single-junction
increased
>19%
may
soon
approach
20%.
This
review
provides
update
recent
progress
OPV
following
aspects:
developments
novel
donors,
understanding
structure–property
relationships
underlying
mechanisms
state-of-the-art
OPVs,
tasks
underpinning
commercialization
such
as
device
stability,
module
development,
potential
applications,
high-throughput
manufacturing.
Finally,
outlook
prospects
section
summarizes
remaining
challenges
technology.
Energy & Environmental Science,
Journal Year:
2021,
Volume and Issue:
14(6), P. 3469 - 3479
Published: Jan. 1, 2021
Regulating
side-chain
orientations
of
Y-series
NFAs
is
a
promising
strategy
to
achieve
favorable
morphology,
and
high
charge
mobility
solar
cell
performances,
which
enables
high-performance
devices
with
efficiency
approaching
18%.
Angewandte Chemie International Edition,
Journal Year:
2021,
Volume and Issue:
60(18), P. 10137 - 10146
Published: Jan. 27, 2021
Abstract
Polymerization
sites
of
small
molecule
acceptors
(SMAs)
play
vital
roles
in
determining
device
performance
all‐polymer
solar
cells
(all‐PSCs).
Different
from
our
recent
work
about
fluoro‐
and
bromo‐
co‐modified
end
group
IC‐FBr
(a
mixture
IC‐FBr1
IC‐FBr2),
this
paper,
we
synthesized
purified
two
regiospecific
substituted
groups
(IC‐FBr‐
o
&
IC‐FBr‐
m
),
which
were
then
employed
to
construct
regio‐regular
polymer
named
PYF‐T‐
,
respectively
.
In
comparison
with
its
isomeric
counterparts
different
conjugated
coupling
sites,
exhibits
stronger
bathochromic
absorption
achieve
better
photon
harvesting.
Meanwhile,
adopts
more
ordered
inter‐chain
packing
suitable
phase
separation
after
blending
the
donor
PM6,
resulted
suppressed
charge
recombination
efficient
transport.
Strikingly,
observed
a
dramatic
difference
between
While
devices
based
on
PM6:PYF‐T‐
can
yield
power
conversion
efficiency
(PCE)
15.2
%,
only
show
poor
efficiencies
1.4
%.
This
demonstrates
success
configuration‐unique
fluorinated
designing
high‐performance
regular
acceptors,
provides
guidelines
towards
developing
all‐PSCs
efficiencies.
Angewandte Chemie International Edition,
Journal Year:
2021,
Volume and Issue:
60(35), P. 19241 - 19252
Published: June 3, 2021
Abstract
A
dissymmetric
backbone
and
selenophene
substitution
on
the
central
core
was
used
for
synthesis
of
symmetric
or
A‐DA′D‐A
type
non‐fullerene
small
molecular
acceptors
(NF‐SMAs)
with
different
numbers
selenophene.
From
S‐YSS‐Cl
to
A‐WSSe‐Cl
S‐WSeSe‐Cl
,
a
gradually
red‐shifted
absorption
larger
electron
mobility
crystallinity
in
neat
thin
film
observed.
exhibit
stronger
tighter
intermolecular
π–π
stacking
interactions,
extra
S⋅⋅⋅N
non‐covalent
interactions
from
benzothiadiazole,
better
ordered
3D
interpenetrating
charge‐transfer
networks
comparison
thiophene‐based
.
The
‐based
device
has
PCE
17.51
%,
which
is
highest
value
selenophene‐based
NF‐SMAs
binary
polymer
solar
cells.
combination
precise
replacement
effective
improve
J
sc
FF
without
sacrificing
V
oc
Angewandte Chemie International Edition,
Journal Year:
2021,
Volume and Issue:
61(19)
Published: Dec. 28, 2021
Semitransparent
organic
solar
cells
(ST-OSCs)
are
considered
as
one
of
the
most
valuable
applications
OSCs
and
a
strong
contender
in
market.
However,
optical
band
gap
current
high-performance
ST-OSCs
is
still
not
low
enough
to
achieve
optimal
balance
between
power
conversion
efficiency
(PCE)
average
visible
transmittance
(AVT).
An
N-substituted
asymmetric
nonfullerene
acceptor
SN
with
over
40
nm
bathochromically
shifted
absorption
compared
Y6
was
designed
synthesized,
based
on
which
device
PM6
donor
obtained
PCE
14.3
%,
accompanied
nonradiative
voltage
loss
0.15
eV.
Meanwhile,
ternary
devices
addition
into
:
can
17.5
%
an
unchanged
open-circuit
improved
short-circuit
current.
Benefiting
from
extended
NIR
lowered
loss,
were
fabricated
optimized
demonstrated
14.0
at
AVT
20.2
highest
20
%.
Accounts of Chemical Research,
Journal Year:
2021,
Volume and Issue:
54(20), P. 3906 - 3916
Published: Oct. 4, 2021
ConspectusOrganic
photovoltaics
(OPVs)
with
a
photoactive
layer
containing
blend
of
organic
donor
and
acceptor
species
are
considered
to
be
promising
technology
for
clean
energy
owing
their
unique
flexible
form
factor
good
solution
processability
that
can
potentially
address
the
scalability
challenges.
The
delicate
designs
both
donors
acceptors
have
significantly
enhanced
power
conversion
efficiency
OPVs
more
than
18%.
Nonfullerene
small-molecule
(NFAs)
played
critical
role
in
enhancing
short-circuit
current
density
(JSC)
by
efficiently
harvesting
near-infrared
(NIR)
sunlight.
To
take
full
advantage
abundant
NIR
photons,
optical
band
gap
NFAs
should
further
reduced
improve
performance
OPVs.
Incorporating
highly
polarizable
selenium
atoms
onto
backbone
conjugated
materials
has
been
proven
an
effective
way
decrease
gap.
For
example,
selenium-substituted
NFA
recently
developed
our
group
attained
JSC
approximate
27.5
mA
cm-2
OPV
devices,
surpassing
those
most
emerging
photovoltaic
systems.
Inspired
this
advance,
we
concentrate
on
topic
selenium-containing
Account
incite
readers'
interest
exploring
series
materials.In
Account,
first
compare
differences
among
chalcogen
heterocycles
discuss
influence
fundamental
electronic
behavior
collective
photoelectrical
properties
resulting
materials.
superior
features
summarized
as
follows:
(1)
large
covalent
radius
diminish
π-orbital
overlap,
rendering
quinoidal
resonance
character
narrowed
(2)
atom
is
sulfur
its
larger
looser
outermost
electron
cloud,
enabling
intermolecular
Se-Se
interaction
increased
charge
carrier
mobility
relevant
solid
state.
We
then
focus
summarizing
design
rules
various
categories
including
polymer
donors,
acceptors,
especially
composed
ladder-type
polycyclic
units.
motivation
incorporating
into
these
structure-property
relationships
were
thoroughly
elucidated.
Specifically,
changes
gap,
mobility,
molecular
packing
induced
substitution
correlate
effects
exciton
behaviors,
loss,
nanoscale
film
morphology
corresponding
devices.
Furthermore,
point
out
intrinsic
stability
under
maximum-power-point
tracking
long-term
photo-
or
thermostress
indicate
potential
use
semitransparent
tandem
solar
cells.
At
end,
prospect
future
research
focuses
possible
applications
field
discussed.
Chemical Reviews,
Journal Year:
2023,
Volume and Issue:
123(13), P. 8395 - 8487
Published: June 5, 2023
The
assembly
of
conjugated
organic
molecules
from
solution
to
solid-state
plays
a
critical
role
in
determining
the
thin
film
morphology
and
optoelectronic
properties
solution-processed
electronics
photovoltaics.
During
evaporative
processing,
π-conjugated
systems
can
assemble
via
various
forms
intermolecular
interactions,
forming
distinct
aggregate
structures
that
drastically
tune
charge
transport
landscape
solid-state.
In
blend
composed
donor
polymer
acceptor
molecules,
neat
materials
couples
with
phase
separation
crystallization
processes,
leading
complex
transition
pathways
which
govern
morphology.
this
review,
we
provide
an
in-depth
review
molecular
processes
polymers
nonfullerene
small
molecule
acceptors
discuss
their
impact
on
properties.
We
then
shift
our
focus
relevant
solar
cells
fundamentals
highlight
how
processing
conditions
affect
device
performance.
Nature Communications,
Journal Year:
2023,
Volume and Issue:
14(1)
Published: April 22, 2023
Abstract
Fullerene
acceptors
typically
possess
excellent
electron-transporting
properties
and
can
work
as
guest
components
in
ternary
organic
solar
cells
to
enhance
the
charge
extraction
efficiencies.
However,
conventional
fullerene
small
molecules
suffer
from
undesirable
segregation
dimerization,
thus
limiting
their
applications
cells.
Herein
we
report
use
of
a
poly(fullerene-
alt
-xylene)
acceptor
(PFBO-C12)
component
enables
significant
efficiency
increase
16.9%
for
binary
18.0%
all-polymer
Ultrafast
optic
optoelectronic
studies
unveil
that
PFBO-C12
facilitate
hole
transfer
suppress
recombination.
Morphological
investigations
show
blends
maintain
favorable
morphology
with
high
crystallinity
smaller
domain
size.
Meanwhile,
introduction
reduces
voltage
loss
light
stability
mechanical
durability
flexible
devices.
This
demonstrates
introducing
polyfullerenes
is
an
effective
approach
achieving
highly
efficient
good
robustness.
Advanced Functional Materials,
Journal Year:
2021,
Volume and Issue:
31(25)
Published: May 2, 2021
Abstract
In
this
paper,
a
difluoro‐monobromo
end
group
is
designed
and
synthesized,
which
then
used
to
construct
novel
polymer
acceptor
(named
PY2F‐T)
yielding
high‐performance
all‐polymer
solar
cells
with
15.22%
efficiency.
The
fluorination
strategy
can
increase
the
intramolecular
charge
transfer
interchain
packing
of
previous
PY‐T
based
acceptor,
significantly
improve
photon
harvesting
mobility
resulting
acceptor.
addition,
detailed
morphology
investigations
reveal
that
PY2F‐T‐based
blend
shows
smaller
domain
spacing
higher
purity,
suppress
recombination
as
supported
by
time‐resolved
techniques.
These
properties
enable
simultaneously
enhanced
J
SC
FF
devices,
eventually
delivering
device
efficiencies
over
15%,
outperforming
devices
on
non‐fluorinated
(13%).
More
importantly,
active
layers
be
processed
under
ambient
conditions
still
achieve
14.37%
They
also
using
non‐halogenated
solvent
o
‐xylene
(no
additive)
yield
decent
performance
13.05%.
This
work
demonstrates
success
in
design
acceptors,
provide
guidelines
for
developing
new
all‐PSCs
better
stabilities
commercial
applications.