Proceedings of Asia-Pacific Conference on Perovskite, Organic Photovoltaics&Optoelectronics (IPEROP25)
Publication date: 17th October 2024
So far, most scientists have investigated how to improve the packing of polymer chains based on the framework of Stille/Suzuki coupling. However, the highly toxic Pd catalyst used in Stille/Suzuki coupling is harmful to the environment. Thus, aldol condensation has drawn people's attention in these years[1]. In this presentation, we show that the chain conformation and coplanarity of conjugated polymers can be modulated by aldol condensation. By optimizing the chain conformation and interchain charge transfer effects, our synthesized polymers deliver efficient ambipolar charge transfer properties, which are among the best values reported for conjugated polymers synthesized by Aldol condensation. Figure 1a showed that the polymers were synthesized with an acidic organic catalyst, p-Toluenesulfonic acid (PTSA). To investigate optical behaviors, solution and film UV absorption was measured and plotted in Figure 1b. Interestingly, polymers with a higher proportion of BDOPV tend to have a greater bathochromic shift in their absorption peaks, especially for BDOPV75, implying that the polymers may have a stronger aggregation. In the gaussian simulation, BDOPV100 shows a larger dihedral angle (33.8°), whereas BDOPV0 presents a planarized backbone. Based on these results, we believe that the dihedral angle will differentiate the polymer stacking behaviors. The OFETs based on these polymers were then fabricated. BDOPV100 showed µh of 8.55 x 10-2 cm2V-1s-1, and µe of 1.01 x 10-2 cm2V-1s-1. However, BDOPV75 could only achieve µh of 5.04 x 10-5 cm2V-1s-1, and µe of BDOPV75 could only last at 2.17 x 10-4 cm2V-1s-1.