Performance of bulk heterojunction photovoltaic devices prepared by airbrush spray deposition

We have used airbrush spray deposition to fabricate organic photovoltaic devices with an active layer composed of a blend of poly(3-hexylthiophene) and [6,6]-phenyl-${\mathrm{C}}_{61}$ butyric acid methyl ester. Working devices were prepared in ambient conditions from a variety of common organic solvents; active layers prepared from chlorobenzene exhibit improved homogeneity, resulting in narrower distributions of the relevant device parameters. Further studies on devices prepared from chlorobenzene showed that annealing at $120°\mathrm{C}$ for $10\min$ resulted in optimum performance, and that an active layer thickness of $150\mathrm{nm}$ resulted in a maximum efficiency of 2.35% under AM1.5 illumination at $1\text{sun}$ .