Bi-hierarchical nanostructures of donor-acceptor copolymer and fullerene for high efficient bulk heterojunction solar cells
Journal
Energy and Environmental Science
Journal Volume
6
Journal Issue
6
Pages
1938-1948
Date Issued
2013
Author(s)
Abstract
Solvent additive processing has become the most effective method to tune the nanostructure of donor-acceptor (D-A) type copolymer/fullerene bulk heterojunctions (BHJs) solar cells for improving power conversion efficiencies. However, to date qualitative microscopic observations reveal discrepant results on the effects of solvent additives. Here, we present quantitative evolution of bi-hierarchical nanostructure of D-A copolymers and fullerenes by employing grazing-incidence small/wide angle X-ray scattering (GISAXS/GIWAXS) techniques and [2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]-dithiophene)- alt-4,7-(2,1,3-benzothiadiazole)]/[6,6]-phenyl-C71-butyric acid methyl ester (PCPDTBT/PCBM) BHJ as model materials. An accurate GISAXS model analysis is established herein for revealing the distinctive bi-hierarchical nanostructures from molecular level to a scale of hundreds of nanometers. The mechanisms of hierarchical formation and mutual influence between PCPDTBT and PCBM domains are proposed to correlate with photovoltaic properties. These results provide a comprehensive interpretation in respect to previous studies on the nanostructures of D-A copolymer/fullerene BHJs. It is helpful for optimum structural design and associated synthesis improvement for achieving high efficiency BHJ solar cells. © 2013 The Royal Society of Chemistry.
SDGs
Other Subjects
2 ,1 ,3-Benzothiadiazole; Bulk heterojunction; Bulk heterojunction solar cells; Donor-acceptor copolymers; Microscopic observations; Optimum structural design; Photovoltaic property; Solvent additives; Additives; Copolymers; Fullerenes; Nanostructured materials; Solar cells; Structural optimization; Heterojunctions; energy efficiency; fuel cell; fullerene; photovoltaic system; polymer; renewable resource; solar power
Type
journal article