Soluble squaraine derivatives for 4.9% efficient organic photovoltaic cells†
Abstract
A series of soluble squaraine derivatives has been designed and developed as a donor material for solution-processible organic photovoltaic cells. In combination with [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as an acceptor, we obtained a power conversion efficiency of 4.86% from bulk-heterojunction photovoltaic cells.