Predicting polaron mobility in organic semiconductors with the Feynman variational approach

2022/07/14 by Martin, Bradley A. A., Frost, Jarvist Moore
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)

paper · doi:10.48550/arxiv.2207.06846

Abstract

We extend the Feynman variational method applied to the parabolic-band Fröhlich (continuum) large polaron~\citeFeynman1955 to a Holstein (lattice) small polaron, with a parabolic-band. This new theory shows a discrete localisation as a function of coupling strength. Having build the theory with the same quasi-particle Lagrangian as the 1955 work, we can directly use the FHIP~\citeFeynman1962 response theory to calculate DC mobility and complex conductivity. We show that we can take matrix elements from electronic structure calculations on real materials, by modelling charge-carrier mobility in crystalline Rubrene. Good agreement is found to measurement, with a predicted mobility of μ= 47.72~\sicm² V^-1 s^-1 at 300~\siK.

Related

• Theory of small-polaron band conduction in ultrapure organic crystals
• Quantum-Classical Study of Charge Transport in Organic Semiconductors with Multiple Low-Frequency Vibrational Modes
• Double path-integral method for obtaining the mobility of the\n one-dimensional charge transport in molecular chain
• Nature of Charge Carriers in Disordered Organic Molecular Semiconductors
• Charge transport in organic semiconductors from the mapping approach to surface hopping