Inverted Organic Solar Cells with Annealing Treated ZnPc(OC₈H₁₇OPyCH₃I)₈ Cathode Buffer Layer

The inverted organic solar cells with ZnPc(OC₈H₁₇OPyCH₃I)₈ film as cathode buffer layer and P3HT: PCBM as active layer were fabricated. The cathode buffer layers were treated by the solvent vapor and airflow annealing to investigate the effect of the annealing treatment methods on the device performance. The results indicate that the annealing treatment can effectively improve the morphology of the buffer layers. The power conversion efficiency(PCE) of the solar cell is improved from 2.14% to 3.76%, the current intensity(J_sc) increases from 8.12 mA/cm² to 10.71 mA/cm², and the fill factor(FF) is improved from 0.45 to 0.61 for the annealing process. More importantly, the stability of the device is enhanced, with the device life being 1.4 times that of the conventional device. This simple cathode interface treatment method provides an effective way to improve the performance of polymer solar cells.