High Efficient P3HT:PCBM Solar Cells via Morphology Manipulating in Active Layer by Rod-Coil Block Copolymer Compatiblizers

The poly(3-hexylthiophene) (P3HT)-based block copolymers were synthesized with hydrophilic and hydrophobic dielectric blocks including poly(ethylene glycol) (PEG), poly(methyl methacrylate) (PMMA), and poly(styrene) (PS), and employed as morphology compatibilizers (1080 wt%) in P3HT: phenyl-C71-butyric acid methyl ester (PCBM) bulk heterojunction (BHJ) solar cells. Compatiblizers simultaneously controlled some main properties, i.e., crystallinity, d-spacing, domain sizes, and stability. Hydrophobic-based compatibilizers (P3HT-b-PS and P3HT-b-PMMA) increased crystallinity, P3HT crystallite size, and PCBM cluster size and decreased d-spacings. This reflected larger and denser P3HT crystallites and coarser and more packed PCBM clusters. Impressing trends of the P3HT-b-PMMA compatibilizers resembled that of P3HT-b-PS ones, but with a smoother slope. In contrast, hydrophilic-based compatibilizers (P3HT-b-PEG and P3HT-b-PEG-b-P3HT) resulted in finer and looser P3HT crystallites and PCBM clusters. Unlike PEG-based compatibilizers, in P3HT-b-PS and P3HT-b-PMMA ones, lower P3HT molecular weights conduced to higher power conversion efficiencies (PCE = 4.43%). Maximum cell characteristics were 11.68 mA/Cm2, 0.63 V, and 63%.

کلیدواژه ها:

P3HT ، PEG ، PMMA ، PS ، PCBM ، BHJ ، PCE