[21p-C601-1~23] 12.5 Organic and hybrid solar cells

5:15 PM - 5:30 PM JST(8:15 AM - 8:30 AM UTC)

[21p-C601-14] Impact of polymer rigidity on charge generation in nonfullerene organic photovoltaics with low voltage loss

〇(M2)Shota Suruga¹, Tsubasa Mikie¹, Yuki Sato², Hyung Do Kim², Hideo Ohkita², Itaru Osaka¹ (1.Hiroshima Univ., 2.Kyoto Univ.)

Keywords:

organic photovoltaics,semiconducting polymer,voltage loss

To further improve the power conversion efficiencies of organic photovoltaics (OPVs), it is a formidable challenge to overcome the trade-off between voltage loss and charge generation. We recently developed a dithienonaphthobisthiadiazole-based π-conjugated polymer (PTNT1-F), which enabled small nonradiative voltage loss (ΔV_nr) and high charge generation efficiency in nonfullerene-based OPVs. Here, we have newly synthesized PTNT1-F analogs, having the same backbone but longer alkyl groups. Whereas the PTNT1-F analogs exhibited almost the same open-circuit voltages and the ΔV_nrs, which reflect that the similar HOMO energy levels, the short-circuit current density appeared to be higher in the polymers with shorter alkyl groups. Importantly, it is suggested that the highly rigid backbone of the polymer in blend films facilitates charge generations.