Anode modification of BHJ organic photovoltaics using copper oxide

Abstract

In this work, the influence of the incorporation of copper oxide films, used to enhance hole extraction/collection, on the optical and electrical properties of bulk heterojunction (BHJ) organic photovoltaics (OPVs), is demonstrated. A significant increase in device efficiency were obtained in OPVs based on the poly(3hexylthiophene) (P3HT) and [6,6]-phenyl-C71 butyric acid methyl ester (PC 71 BM) bulk heterojunctions. This was achieved by introducing a copper oxide layer, after optimizing its thickness to 20 nm, at the anode/organic layer interface instead of the commonly used poly(styrenesulfonate)-doped poly(ethylenedioxythiophene) (PEDOT:PSS). The increased efficiency was attributed to the increase of Fill Factor (FF) and the reduction in the device series resistance, when PEDOT:PSS was replaced by these metal oxide layers.