PS-b-PMMA templated ITO electrodes for improving the performance of non-fullerene organic photovoltaics

Abstract

We have developed a block copolymer (BCP)-based patterned electrode with a periodic structure of 80 nm and investigated their application in organic photovoltaics. The indium tin oxide (ITO) electrodes with the thicknesses of 30, 50, 70, 90, and 120 nm were sputtered onto BCP-patterned templates and the morphology and optoelectronic properties were investigated. Using the finite difference in time domain method, the effect of different thickness electrodes on the light absorption of the active layer was studied. We found that the ITO thickness of 70 nm has an absorption enhancement effect in the visible wavelength band. Finally, we prepared organic photovoltaic devices based on the non-fullerene PBDB-T:ITIC system, the BCP-patterned templates enhance greatly the light absorption of the active layer through both light diffraction and coupling to surface plasmon polariton modes achieving a 12.9% increase in power conversion efficiency. • ITO electrodes with 80 nm periodic structure were developed by BCP self-assembly. • Patterned ITO greatly enhance the light absorption of the PBDB-T:ITIC active layer. • OPVs with patterned ITO achieve a 12.9% increase in power conversion efficiency.