Facile Method for Fabrication of Nanostructured CuPC Thin Films To Enhance Photocurrent Generation

It has been demonstrated that bulk heterojunction with controlled nanostructures is needed to improve the performance of the organic solar cells. But, simple methods for production of such nanostructure are still rare. We found that when several drops of chloroform, toluene, or acetone were added on the surface of vacuum-deposited CuPC films, nanorods with diameters of about 50 nm could be obtained after the evaporation of the solvent. The size, shape, and orientation of these nanostructures changed with the solvent used. In comparison with the flat bilayer cells, significant increase in photocurrent generation was observed in the bilayer cells based on such nanostructured films with a spin-coated [6,6]-phenyl- C 61 -butyric acid methyl ester thin film as the acceptor materials. The nanostructures with more ordered orientation that resulted from acetone treating displayed the largest enhancement in the photocurrent generation.