Effect of Solvent Annealing in the Presence of Electric Field on P3HT:PCBM Films Used in Organic Solar Cells

The performance of poly-3-hexyl thiophene (P3HT) blended with (6,6) phenyl C₆₁ butyric acid methyl ester (PCBM)-based bulk heterojunction solar cells is known to improve with thermal annealing of the P3HT:PCBM device active layer during its formation by the solvent-drying step. In this paper, we have proposed carrying out the annealing for solvent drying in the presence of a constant electric field across active layer film solution. Comparative studies of film morphology and electrooptical properties of the film and devices have been presented to understand the effect of the electric field during the solvent annealing of the device active layer. The external quantum efficiency and power conversion efficiency of the solar cells made is found to be significantly enhanced in devices that were subject to an electric field during the solvent-annealing steps.