PolaronMobility.jl: Implementation of the Feynman variational polaron model
Jarvist Moore Frost · The Journal of Open Source Software · 2018
An additional electron (i.e. a charge carrier) in a material applies a polarisation field.In a polar material (one where the ions of the lattice have different charge), this results in a large coupling into the lattice motion.Small distortions in the lattice can be described in terms of a harmonic restoring force, and thereby a harmonic quasi-particle of vibration termed a phonon.Electron-phonon coupling provides a scattering mechanism by which momentum (kinetic-energy) of an electron is dissipated.These scattering processes limit charge-carrier mobility in materials.Being able to predict charge-carrier mobility helps the computational design of new technological materials.Many new materials of potential utility and interest are polar.These include oxides used as battery anodes and transparent conductors for electronic displays; and chalcogenides and halides indicated for light emission (displays, lighting) and absorption (photovoltaic solar cells).