Thermal Annealing Effects on the Fine Structure and Performance of P3HT: PCBM Based Organic Solar Cells Fabricated in Air

Abstract

The annealing treatment effects on the nanostructure of the active layer based on P3HT and PCBM and its relation to the solar cell performance was studied. The UV-visible absorption spectra and the x-ray diffraction patterns indicated enhanced crystallinity upon annealing. The AFM showed that annealing increased surface roughness and the effect is more pronounced for the higher annealing temperature. J-V characteristics of the organic solar cells showed an enhanced performance for the active layer annealed at 140 • C compared to that annealed at 80 • C with efficiencies of 2.7% and 0.31% respectively.