writer：Guangmin Wei; Xinxin Li; Di Jia; He Cheng*
keywords：P3HT-azide-PCBM, microgel, light scattering
source：期刊
specific source：Journal of Nanoscience and Nanotechnology
Issue time：2016年
Spherical Poly(3-hexylthiophene)-azide-[6,6]-phenyl-C61-butyric acid methyl ester (P3HT-azide-
PCBM) microgel was synthesized by introducing an azide cross-linkable group into the conjugated
polymer. Its UV-vis spectrum shifts blue as a result of the systematic disruption of planarity along
the P3HT backbone and a reduction in long range conjugation. And the corresponding fluorescence
spectrum also indicates that a strong intra-molecular photo-induced electron transfer is originated
from the covalent linkage of PCBM moiety to the P3HT backbone via the hexyl bridge upon photoexcitation.
Combined Gel Permeation Chromatography (GPC), dynamic and static light scattering
(DLS and SLS) measurements prove that the resultant P3HT-azide-PCBM copolymer is a uniform
spherical microgel with a hydrodynamic radius of 130 nm at room temperature. The spherical
P3HT-azide-PCBM microgel can be used as electron donor or compatibilizer in bulk-heterojunction
(BHJ) devices, but its introduction reduces the photovoltaic performance compared with the blend
of P3HT/PCBM, because the hole mobility in the crosslinked polythiophene backbones is largely
decreased.