10.1021/acsami.5b02456.s001
Tsubasa Mikie
Tsubasa
Mikie
Akinori Saeki
Akinori
Saeki
Naohiko Ikuma
Naohiko
Ikuma
Ken Kokubo
Ken
Kokubo
Shu Seki
Shu
Seki
Hetero
Bis-Addition of Spiro-Acetalized or Cyclohexanone Ring to 58π
Fullerene Impacts Solubility and Mobility Balance in Polymer Solar
Cells
American Chemical Society
2015
SCLC
circuit voltage
SAF 5 monoadduct
electrochemical property
device PCEs
power conversion efficiency
LUMO
bulk heterojunction
58π Fullerene Impacts Solubility
PCBM
OPV
counter monoadducts
CH
Voc
Cyclohexanone Ring
Mobility Balance
mobility balance
P 3HT
0.80 V
56π fullerenes
2015-06-17 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Hetero_Bis_Addition_of_Spiro_Acetalized_or_Cyclohexanone_Ring_to_58_Fullerene_Impacts_Solubility_and_Mobility_Balance_in_Polymer_Solar_Cells/2205124
Fullerene bis-adducts are increasingly
being studied to gain a high open circuit voltage (<i>V</i><sub>oc</sub>) in bulk heterojunction organic photovoltaics (OPVs).
We designed and synthesized homo and hetero bis-adduct [60]fullerenes
by combining fused cyclohexanone or a five-membered spiro-acetalized
unit (SAF<sub>5</sub>) with 1,2-dihydromethano (CH<sub>2</sub>), indene,
or [6,6]-phenyl-C<sub>61</sub>-butyric acid methyl ester (PCBM). These
new eight 56π fullerenes showed a rational rise of the lowest
unoccupied molecular orbital (LUMO). We perform a systematic study
on the electrochemical property, solubility, morphology, and space-charge-limited
current (SCLC) mobility. The best power conversion efficiency (PCE)
of 4.43% (average, 4.36%) with the <i>V</i><sub>oc</sub> of 0.80 V was obtained for poly(3-hexylthiophene) (P3HT) blended
with SAF<sub>5</sub>/indene hetero bis-adduct, which is a marked advancement
in PCE compared to the 0.9% of SAF<sub>5</sub> monoadduct. More importantly,
we elucidate an important role of mobility balance between hole and
electron that correlates with the device PCEs. Besides, an empirical
equation to extrapolate the solubilities of hetero bis-adducts is
proposed on the basis of those of counter monoadducts. Our work offers
a guide to mitigate barriers for exploring a large number of hetero
bis-adduct fullerenes for efficient OPVs.