Giunchi Andrea, Pandolfi Lorenzo, Della Valle Raffaele G, Salzillo Tommaso, Venuti Elisabetta, Girlando Alberto
Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna, Viale del Risorgimento, 4, 40136 Bologna, Italy.
Molecular Materials Group, Strada Fontanini 68, 43124 Parma, Italy.
Cryst Growth Des. 2023 Jul 31;23(9):6765-6773. doi: 10.1021/acs.cgd.3c00634. eCollection 2023 Sep 6.
Polarized low-frequency Raman microscopy and a posteriori dispersion-corrected density functional simulations are combined to investigate the lattice vibrations of the α, β, and γ polymorphs of the model organic semiconductor quinacridone, which are known to display different optical and electronic properties. The comparison between experiments and calculations allows for unambiguous mode assignment and identification of the scattering crystal faces. Conversely, the agreement between simulations and experiments validates the adopted computational methods, which correctly describe the intermolecular interaction of the molecular material. The acquired knowledge of quinacridone lattice dynamics is used to describe the α to β thermal transition and, most consequentially, to reliably characterize the electron-lattice phonon coupling strength of the three polymorphs, obtaining hints about the electrical transport mechanism of the material.
将偏振低频拉曼显微镜与后验色散校正密度泛函模拟相结合，以研究模型有机半导体喹吖啶酮的α、β和γ多晶型物的晶格振动，已知这些多晶型物具有不同的光学和电子性质。实验与计算之间的比较使得能够明确地进行模式归属并识别散射晶体面。相反，模拟与实验之间的一致性验证了所采用的计算方法，该方法正确地描述了分子材料的分子间相互作用。所获得的关于喹吖啶酮晶格动力学的知识被用于描述α到β的热转变，最重要的是，可靠地表征三种多晶型物的电子-晶格声子耦合强度，从而获得有关该材料电输运机制的线索。
