Active layers for organic photovoltaic devices (OPVs) were prepared by hand drawing with paint marker pens containing solutions of the materials. Although the pen-coated organic films were visually non-uniform with quite high surface roughness, OPV devices using these films exhibited similar or slightly better performances than those using spin-coated films. As such, the pen-coating technique represents an easily accessible, inexpensive, and highly material-efficient method for fabricating OPVs.
