Influence of cathode sputter deposition on organic solar cells

The sputter deposition technique is usually avoided for organic solar cells, despite its technological advantages, because it may potentially damage the organic absorber layer. The consequences of sputtering on device performance-presumably related to changes in the absorber morphology and defect distribution near the interface-are discussed. Despite its negative influence on as-deposited samples, sputtering in combination with thermal annealing can actually be beneficial for pure aluminum contacts, leading to efficiencies even better than those of cells with thermally evaporated cathodes, mainly due to an enhanced open-circuit voltage.