Electron-phonon coupling and mobility modeling in organic semiconductors: Method and application to two tetracene polymorphs

We have developed a first-principles method to calculate the electron-phonon coupling for specific modes and q points in the Brillouin zone for crystalline organic semiconductors. Using the obtained coupling strengths, we propose an approach to compute the temperature-dependent mobilities of electrons and holes. To validate our treatment of the electronic structures and vibrational properties, we calculate the Raman spectra in the lattice-phonon region and compare them with experimental data. We then compare the computed mobilities with available data for single crystals of naphthalene, anthracene, and tetracene (bulk polymorph), finding good agreement within the experimental range, especially when accounting for possible charged impurities. Finally, we discuss the observed differences between tetracene polymorphs.