Organic photovoltaic devices based on pentacene/N,N′-dioctyl-3,4,9,10-perylenedicarboximide heterojunctions

We have studied an organic photovoltaic cell based on an efficient donor/acceptor combination of pentacene/N,N′-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) heterojunctions. Photocurrent spectra exhibited excellent light harvesting throughout the visible spectrum with maximum external quantum efficiency (EQE) of ∼60%. PTCDI-C8 layer provided significant contribution to the photocurrent due to its strong absorption properties and efficient exciton dissociation at pentacene/PTCDI-C8 interface. Power conversion efficiency of about 1.2% has been achieved under AM 1.5 illumination. The device showed a low series resistance of 18 Ω cm2 and a high shunt resistance of 2.5 kΩ cm2, resulting in a high fill factor of 65%.