The effect of solvent on the morphology of an inkjet printed active layer of bulk heterojunction solar cells

Vivi Fauzia, Akrajas Ali Umar, Muhamad Mat Salleh and Muhammad Yahaya

Abstract

Bulk heterojunction organic solar cells were fabricated by sandwiching the active layer between indium tin oxide (ITO) and Al electrodes. The active layer used was a blend of poly(3-octylthiophene-2,5-diyl) (P3OT) as the electron donor and (6,6)-phenyl C₇₁ butyric acid methyl ester (PC₇₁BM) as the electron acceptor. The active layer thin films were deposited by an inkjet printing technique. Prior to deposition of the thin films, the active materials were blended in three different solvents. The printed films were annealed at three different temperatures. It was found that the selection of the appropriate solvent and annealing treatment significantly influences the printing process, the morphology of the printed film and subsequently the performance of the solar cell devices