[21a-E101-1~12] 12.5 Organic solar cells

△ [21a-E101-12] Dimensionality of singlet exciton diffusion in crystalline phase of conjugated polymer

〇Yasuhiro Murata¹, Kento Yamaguchi¹, Yasunari Tamai^1,2, Hideo Ohkita¹ (1.Kyoto Univ., 2.JST PRESTO)

Keywords:transient absorption spectroscopy, energy transfer, aggregate

We study diffusion dynamics of singlet excitons in crystalline phases of a conjugated polymer PNOz4T, which is likely to form intrachain ordered J-aggregated crystalline structures, measured by transient absorption decays from 294 to 78 K. By analyzing the time dependence of singlet–singlet annihilation (SSA) rate, we evaluated the diffusion coefficient D and the dimensionality of exciton diffusion in the PNOz4T film. As a result, we found that two-dimensional diffusion is dominant in the J-aggregated PNOz4T film at room temperature and one-dimensional diffusion is dominant at low temperatures. These findings suggest that the excitonic couplings and activation energy in intra- and inter-chain directions have impact on the dimensionality of the singlet exciton diffusion.