A series
of alk
oxy-substituted dihydr
onaphthyl-based [60]fullerene bisadduct derivatives (C
n-NCBA,
n = 1鈥?), with the alk
oxy chain length fr
om 1 t
o 6 carb
on at
oms, were synthesized as accept
ors f
or p
olymer s
olar cells (PSCs), f
or the purp
ose
of systematically investigating the effects
of fullerene derivative structures
on the ph
ot
ov
oltaic pr
operties
of PSCs. Alth
ough the abs
orpti
on spectra and electr
ochemical pr
operties
of C
n-NCBA are alm
ost the same, the PSCs based
on P3HT:C
n-NCBA sh
owed different ph
ot
ov
oltaic pr
operties. The device based
on the P3HT:C3-NCBA blend dem
onstrated the highest p
ower-c
onversi
on efficiency (PCE)
of ca. 4.1%, while th
ose with sh
orter
or l
onger alk
oxy-substituted dihydr
onaphthyl-based [60]fullerene bisadduct derivatives sh
owed relatively l
ower PCE values. C5-NCBA and C6-NCBA with l
onger alk
oxy chain length sh
owed relatively l
ow electr
on m
obilities, leading t
o relatively p
oor ph
ot
ov
oltaic perf
ormance. M
ore imp
or
tantly, we f
ound that the alk
oxy chain length changes the hydr
oph
obicity
of C
n-NCBA and, thus, the interfacial interacti
on and miscibility with P3HT, which were analyzed by interfacial tensi
on and at
omic f
orce micr
osc
opy (AFM) measurements. The hydr
oph
obicity
of C
n-NCBA increased as the alk
oxy chain length increased. A distinct phase separati
on f
or the P3HT:C1-NCBA blend film due t
o the large interfacial tensi
on and p
oor miscibility between P3HT and C1-NCBA c
ould be
one reas
on f
or the l
ow PCE value
of the C1-NCBA-based devices. C3-NCBA may pr
ovide the m
ost appr
opriate c
ombinati
on
of electr
on m
obility and miscibility with P3HT t
o achieve
optimal ph
ot
ov
oltaic pr
operties. The current study pr
ovides the m
olecular structure鈥揹evice perf
ormance relati
onship, especially with respect t
o the alk
oxy chain length
of C
n-NCBA and their interfacial interacti
ons with P3HT, and suggests a design rule f
or high-perf
ormance fullerene bisadduct accept
ors f
or PSC applicati
ons.
Keywords:
ors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=polymer+solar+cell&qsSearchArea=searchText">polymer solar cell; ors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=electron+acceptor&qsSearchArea=searchText">electron acceptor; ors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=bisadduct+fullerene&qsSearchArea=searchText">bisadduct fullerene; ors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=chain+length&qsSearchArea=searchText">chain length; ors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=miscibility&qsSearchArea=searchText">miscibility; ors" href="http://pubs.acs.org/action/doSearch?action=search&searchText=electron+mobility&qsSearchArea=searchText">electron mobility