Head-to-Head Linkage Containing Bithiophene-Based Polymeric Semiconductors for Highly Efficient Polymer Solar Cells

Adv Mater. 2016 Dec;28(45):9969-9977. doi: 10.1002/adma.201603112. Epub 2016 Sep 22.

Abstract

Narrow bandgap (1.37-1.46 eV) polymers incorporating a head-to-head linkage containing 3-alkoxy-3'-alkyl-2,2'-bithiophene are synthesized. The head-to-head linkage enables polymers with sufficient solubility and the noncovalent sulfur-oxygen interaction affords polymers with high degree of backbone planarity and film ordering. When integrated into polymer solar cells, the polymers show a promising power conversion efficiency approaching 10%.

Keywords: film morphology; organic electronics; polymer semiconductors; polymer solar cells; sulfur-oxygen interactions.