Controlling the excited-state energy levels of 9,9′-bifluorenylidene derivatives by twisting their structure to attaining singlet fission character in organic photovoltaics

Abstract

9,9′-Bifluorenylidene (BFN) derivatives, in which the two fluorene moieties are connected <italic>via</italic> a CC double bond at the 9-position, are expected to show singlet fission (SF) character in organic photovoltaics (OPVs).