A Strategy to Design a Donor-pi-Acceptor Polymeric Hole Conductor for an Efficient Perovskite Solar Cell

Abstract

A strategy for developing a novel donor--acceptor conducting polymeric hole transport material (TTB-TTQ) based on thiophene and benzothiadiazole as an alternative to spiro-MeOTAD is reported. The resulting polymer is highly soluble in many organic solvents and exhibits excellent film formability. The addition of lithium bis(trifluoromethanesulfonyl) imide salt and tert-butylpyridine to TTB-TTQ results in a rough film surface with a fibril structure and improved charge transport. A perovskite solar cell with the highest power conversion efficiency () yet achieved in such cells, 14.1%, which is 22.6% greater than that of a device employing a spiro-MeOTAD is demonstrated. This strategy provides a novel approach to developing solar cell materials for efficient perovskite solar cells.