초록 |
Charge recombination is a major loss process in organic photovoltaics (OPVs). Due the relatively low dielectric constant of organic materials, electrons and holes in the active layer can easily recombine and decay. In this work, we investigated how a Lewis acid doping affects the recombination properties in OPVs based on Poly[4,8-bis(5-(2-ethylhexyl) thiophen-2-yl)benzo[1,2-b:4,5-b’]dithiophene-co-3-fluorothieno[3,4-b] thiophene-2-carboxylate] (PTB7-Th) as a donor and phenyl-C71-butyric acid methyl ester (PC70BM) as an acceptor. Diverse characterization tools, including power density dependent electrical measurement, electrochemical impedance spectroscopy, and charge carrier mobility extraction, were applied to study the charge carrier dynamics in the doped system. |