title: Phonon-Electron Scattering Limits Free Charge Mobility in Methylammonium Lead Iodide Perovskites.
abstract: The nature of the photoconductivity in solution-processed films of methylammonium lead iodide perovskite is investigated by determining the variation of the photoconductive response with temperature. Ultrabroadband terahertz (THz) photoconductivity spectra in the 0.3-10 THz range can be reproduced well by a simple Drude-like response at room temperature, where free charge carrier motion is characterized by an average scattering time. The scattering time determined from Drude fits in the 0.3-2THz region increases from ∼4 fs at 300 K (tetragonal phase; mobility of ∼27 cm(2) V(-1) s(-1)) to almost ∼25 fs at 77 K (orthorhombic phase, mobility of ∼150 cm(2) V(-1) s(-1)). For the tetragonal phase (temperature range 150 < T < 300 K) the scattering time shows a ∼T(-3/2) dependence, approaching the theoretical limit for pure acoustic phonon (deformation potential) scattering. Hence, electron-phonon, rather than impurity scattering, sets the upper limit on free charge transport for this perovskite.
authors.affiliation: Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Melike
authors.initials: M
authors.lastname: Karakus
authors.affiliation: Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Søren A
authors.initials: SA
authors.lastname: Jensen
authors.affiliation: Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Francesco
authors.initials: F
authors.lastname: D'Angelo
authors.affiliation: Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Turchinovich
authors.affiliation: Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Mischa
authors.initials: M
authors.lastname: Bonn
authors.affiliation: Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Enrique
authors.initials: E
authors.lastname: Cánovas
keywords: MAPbI3(Cl); photoconductivity; time-resolved photoluminescence; time-resolved terahertz spectroscopy