Shielded gas annealing: the improvement of optical-electric properties in the PEDOT: PSS layer of polymer solar cells

In this paper, the properties and morphology of poly (3, 4-ethylenedioxythiophene): poly (styrene-sulfonate) (PEDOT: PSS) films fabricated by spin-coating and annealing process at different circumstances were investigated in detail. Compared with vacuum condition, it was found that films annealed in nitrogen have better contact morphology, transmission, and conductivity. In addition, the roughness under nitrogen treatment is also better after spin-coated active layer. Short-circuit current density and fill factor are improved by 65% and 22%, respectively. The annealing process in nitrogen process also enhanced the open-circuit voltage output because of the close contact interface. These result in an improvement of Power conversion efficiency by 147%.