[20p-231C-1~9] Frontier of organic semiconductor crystals: Toward the Molecular Science of Quantum Liberated Electrons

[20p-231C-2] Charge Transport Simulations of Organic Semiconductors Based on First-Principles Calculations -Transport properties by localized and itinerant electrons-

〇Hiroyuki Ishii¹, Nobuhiko Kobayashi¹ (1.Univ. of Tsukuba)

Keywords:organic semiconductor, charge transport, first-principles calculation

To develop new organic semiconductors with higher mobility, it is important to understand how charge carriers propagate in molecular crystal. However, we cannot apply conventional transport theories based on the perturbation theory, such as coherent band transport model and incoherent hopping transport model, to organic semiconductors, since the magnitude of intermolecular transfer integrals is comparable to the magnitude of electron-molecular-vibration couplings. Therefore, we have developed an order-N methodology called “Time-dependent wave-packet diffusion method” to evaluate mobilities of charge carriers coupled with molecular vibrations using quantum dynamics based on first-principles calculations. As a demonstration, we apply it to some representative organic semiconductors and show the calculated mobilities and their temperature dependences are in good agreement with those obtained in experiments. In the presentation, we will discuss the detail of our calculation methodology and the transport mechanism of organic semiconductors.