Bandlike and Polaronic Charge Transport in Organic Crystals from First-Principles

Predicting charge transport in organic molecular crystals (OMCs) is challenging due to their complex crystal structures and electron-phonon (e-ph) interactions. In this talk, we will present two first-principles frameworks to accurately predict the charge carrier mobilities in OMCs. The first is the Boltzmann transport equation (BTE) with ab initio e-ph interactions, which describes the bandlike transport regime in OMCs [1]. We will show BTE calculations of hole mobilities in various molecular systems, and examine the effect of strain on charge transport. The second method is the cumulant plus Green-Kubo (CK) [2,3], which addresses the regime where the e-ph interactions are of intermediate strength and the charge carriers form polarons. We will present our recent CK calculations of electron mobilities and electron spectral functions in OMCs. Both our BTE and CK approaches provide mobilities in very good agreement with experiments over a wide temperature range. These broadly applicable methods advance the understanding of charge transport in organic semiconductors.

 

[1] Lee et al., Phys. Rev. B, 97, 115203 (2018)

[2] Zhou et al., Phys. Rev. Research, 1, 033138 (2019)

[3] Chang et al., arXiv:2106.09810