Postfabrication annealing of pentacene-based photovoltaic cells

We studied the effects of postfabrication annealing on heterojunction photovoltaic cells made from vacuum deposited pentacene and C60. The maximum power conversion efficiency under 115 mW cm2 illumination increases from 0.45% to 1.07% after annealing the cells at 200 °C. The increased performance is a result of better molecular ordering, which leads to an increased shunt resistance and built-in potential. © 2004 American Institute of Physics