Journal of the American Chemical Society,
Journal Year:
2019,
Volume and Issue:
141(19), P. 7743 - 7750
Published: April 22, 2019
Although
significant
improvements
have
been
achieved
for
organic
photovoltaic
cells
(OPVs),
the
top-performing
devices
still
show
power
conversion
efficiencies
far
behind
those
of
commercialized
solar
cells.
One
main
reasons
is
large
driving
force
required
separating
electron–hole
pairs.
Here,
we
demonstrate
an
efficiency
14.7%
in
single-junction
OPV
by
using
a
new
polymer
donor
PTO2
and
nonfullerene
acceptor
IT-4F.
The
device
possesses
efficient
charge
generation
at
low
force.
Ultrafast
transient
absorption
measurements
probe
formation
loosely
bound
pairs
with
extended
lifetime
that
impedes
recombination
carriers
blend.
theoretical
studies
reveal
molecular
electrostatic
potential
(ESP)
between
IT-4F
large,
induced
intermolecular
electric
field
may
assist
generation.
results
suggest
OPVs
further
improvement
judicious
modulation
ESP.
Science,
Journal Year:
2018,
Volume and Issue:
361(6407), P. 1094 - 1098
Published: Aug. 9, 2018
Although
organic
photovoltaic
(OPV)
cells
have
many
advantages,
their
performance
still
lags
far
behind
that
of
other
platforms.
A
fundamental
reason
for
low
is
the
charge
mobility
materials,
leading
to
a
limit
on
active-layer
thickness
and
efficient
light
absorption.
In
this
work,
guided
by
semi-empirical
model
analysis
using
tandem
cell
strategy
overcome
such
issues,
taking
advantage
high
diversity
easily
tunable
band
structure
record
certified
17.29%
power
conversion
efficiency
two-terminal
monolithic
solution-processed
OPV
achieved.
Advanced Materials,
Journal Year:
2020,
Volume and Issue:
32(19)
Published: March 29, 2020
Optimizing
the
molecular
structures
of
organic
photovoltaic
(OPV)
materials
is
one
most
effective
methods
to
boost
power
conversion
efficiencies
(PCEs).
For
an
excellent
system
with
a
certain
conjugated
skeleton,
fine
tuning
alky
chains
considerable
significance
fully
explore
its
potential.
In
this
work,
optimization
alkyl
performed
on
chlorinated
nonfullerene
acceptor
(NFA)
named
BTP-4Cl-BO
(a
Y6
derivative)
and
very
impressive
parameters
in
OPV
cells
are
obtained.
To
get
more
ordered
intermolecular
packing,
n-undecyl
shortened
at
edge
BTP-eC11
n-nonyl
n-heptyl.
As
result,
NFAs
BTP-eC9
BTP-eC7
synthesized.
The
shows
relatively
poor
solubility
thus
limits
application
device
fabrication.
Fortunately,
possesses
good
and,
same
time,
enhanced
electron
transport
property
than
BTP-eC11.
Significantly,
due
simultaneously
short-circuit
current
density
fill
factor,
BTP-eC9-based
single-junction
record
maximum
PCE
17.8%
certified
value
17.3%.
These
results
demonstrate
that
minimizing
suitable
packing
has
great
potential
further
improving
performance.
Nature Communications,
Journal Year:
2019,
Volume and Issue:
10(1)
Published: June 7, 2019
Broadening
the
optical
absorption
of
organic
photovoltaic
(OPV)
materials
by
enhancing
intramolecular
push-pull
effect
is
a
general
and
effective
method
to
improve
power
conversion
efficiencies
OPV
cells.
However,
in
terms
electron
acceptors,
most
common
molecular
design
strategy
halogenation
usually
results
down-shifted
energy
levels,
thereby
leading
decreased
open-circuit
voltages
devices.
Herein,
we
report
chlorinated
non-fullerene
acceptor,
which
exhibits
an
extended
meanwhile
displays
higher
voltage
than
its
fluorinated
counterpart
This
unexpected
phenomenon
can
be
ascribed
reduced
non-radiative
loss
(0.206
eV).
Due
simultaneously
improved
short-circuit
current
density
voltage,
high
efficiency
16.5%
achieved.
study
demonstrates
that
finely
tuning
reduce
bandgap-voltage
offset
has
great
potential
for
boosting
efficiency.
