American Chemical Society
Browse

Effect of Pendant Functionality in Thieno[3,4‑b]thiophene-alt-benzodithiophene Polymers for OPVs

Download (834.23 kB)
journal contribution
posted on 2015-01-27, 00:00 authored by Patrick Homyak, Yao Liu, Sunzida Ferdous, Feng Liu, Thomas P. Russell, E. Bryan Coughlin
The performance of organic photovoltaics (OPVs) is heavily dependent on the structure and functionalization of the conjugated polymer used in the active absorbing layer. Using a set of materials based on poly­(thieno­[3,4-b]­thiophene-alt-benzodithiophene) with different alkyl, aryl, perfluoroalkyl, and perfluoroaryl pendant functionalities, we have studied the correlation between absorbance, morphology, crystallinity, charge mobility, and the OPV performance in an effort to identify structure-performance relationships. The perfluorinated pendants on PTF8B and PTFPB were shown to significantly enhance the Voc in the OPV devices (by ∼0.2 V), but also induced the formation of larger phase separated PCBM-rich domains. PT8B and PTFPB devices reached average efficiencies of ∼3.2%.

History