Dilmurat Rishat, Prodhan Suryoday, Wang Linjun, Beljonne David
Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc, 20, 7000 Mons, Belgium.
Key Laboratory of Excited-State Materials of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou 310027, China.
J Chem Phys. 2022 Feb 28;156(8):084115. doi: 10.1063/5.0082569.
Disordered or even seemingly amorphous, donor-acceptor type, conjugated copolymers with high charge-carrier mobility have emerged as a new class of functional materials, where transport along the conjugated backbone is key. Here, we report on non-adiabatic molecular dynamics simulations of charge-carrier transport along chains of poly (indacenodithiophene-co-benzothiadiazole), within a model Hamiltonian parameterized against first-principles calculations. We predict thermally activated charge transport associated with a slightly twisted ground-state conformation, on par with experimental results. Our results also demonstrate that the energy mismatch between the hole on the donor vs the acceptor units of the copolymer drives localization of the charge carriers and limits the intra-chain charge-carrier mobility. We predict that room-temperature mobility values in excess of 10 cm V s can be achieved through proper chemical tuning of the component monomer units.
具有高电荷载流子迁移率的无序甚至看似无定形的供体-受体型共轭共聚物已成为一类新型功能材料，其中沿共轭主链的传输是关键。在此，我们报告了在基于第一性原理计算参数化的模型哈密顿量内，对聚（茚并二噻吩-共-苯并噻二唑）链上电荷载流子传输的非绝热分子动力学模拟。我们预测与略微扭曲的基态构象相关的热激活电荷传输，与实验结果相当。我们的结果还表明，共聚物供体与受体单元上的空穴之间的能量失配驱动电荷载流子的局域化并限制链内电荷载流子迁移率。我们预测，通过对组成单体单元进行适当的化学调谐，可以实现超过10 cm² V⁻¹ s⁻¹ 的室温迁移率值。
