Acceptor Properties of Boron Subphthalocyanines in Fullerene Free Photovoltaics

In this paper, we discuss the use of the typical electron-donor (donor) material boron subphthalocyanine chloride (Cl-BsubPc) and a chlorinated derivative (hexachloro boron subphthalocyanine chloride, Cl-Cl(6)BsubPc) to act as electron-accepting (acceptor) materials and as replacements for Cap when coupled with tetracene and pentacene as the electron-donor materials in organic photovoltaics (OPVs). A large decrease in photocurrent was observed when C-60 was replaced in the pentacene OPVs, although there was evidence of the harvesting of some triplets for the pentacene/Cl-Cl(6)BsubPc OPV. Large increases in V-oc, and stability were observed. Photoluminescence quenching, electron mobilities, and photovoltaic device characteristics are also presented and indicate the ambipolar quality of these small molecule organic semiconductors.