Easily-accessible fullerenol as a cathode buffer layer for inverted organic photovoltaic devices

Abstract

An easily-accessible hydroxyl group-containing fullerene derivative, fullerenol, has been used as a cathode buffer layer (CBL) for inverted polymer solar cells. The performance of the inverted solar cells could be tuned by simply altering the annealing temperature of the fullerenol layer, which was due to the unique thermal-cleavage property of fullerenol. P3HT-PC₆₁BM based cells with fullerenol as buffer layer showed power conversion efficiency (PCE) approaching 3.80%, as control, the bare ITO and ZnO modified ITO devices showed PCEs of 1.92% and 3.42%, respectively.