An oligothiophene chromophore with a macrocyclic side chain: synthesis, morphology, charge transport, and photovoltaic performance

摘要: An oligothiophene chromophore RingBDT(T3A)2 has been synthesized, where BDT is benzo[1,2-b:4,5-b′]dithiophene, Ring a 1,12-dodecylenedioxy cyclic side chain on the benzene of BDT, T3 2,2′:5′,2′′-terthiophene, and A an electron acceptor. In single crystals, immediate precursor formed π-dimers ring prevented further π-stacking dimers. differential scanning calorimetry study showed that BDT(T3A)2, ringless analog with two 2-ethylhexyloxy chains crystallized quickly from its melt upon cooling, while crystallization cooling was slow incomplete. Interestingly, solid fast at ∼110 °C heating, but thin films (200 nm) remained amorphous after annealing 80 °C. Despite nature, hole mobility (1.52 × 10−3 cm2 V−1 s−1) 144% higher than highly crystalline BDT(T3A)2 (200–80 nm). Solar cells were fabricated blends chromophores phenyl-C61-butyric acid methyl ester (PC60BM). Thermal 100 for 10 minutes enhanced π–π interaction, improved device fill factor efficiency blend solar cells, retaining nature blend. stark contrast, thermal under same conditions caused cell to drop by 82%. This demonstrates effectiveness using macrocyclic as strategy developing molecular semiconducting materials morphological stability.