title: Phonon Mode Transformation Across the Orthohombic-Tetragonal Phase Transition in a Lead Iodide Perovskite CH3NH3PbI3: A Terahertz Time-Domain Spectroscopy Approach.
abstract: We study the temperature-dependent phonon modes of the organometallic lead iodide perovskite CH3NH3PbI3 thin film across the terahertz (0.5-3 THz) and temperature (20-300 K) ranges. These modes are related to the vibration of the Pb-I bonds. We found that two phonon modes in the tetragonal phase at room temperature split into four modes in the low-temperature orthorhombic phase. By use of the Lorentz model fitting, we analyze the critical behavior of this phase transition. The carrier mobility values calculated from the low-temperature phonon mode frequencies, via two theoretical approaches, are found to agree reasonably with the experimental value (∼2000 cm(2) V(-1) s(-1)) from a previous time-resolved THz spectroscopy work. Thus, we have established a possible link between terahertz phonon modes and the transport properties of perovskite-based solar cells.
authors.affiliation: Nanoscience and Nanotechnology Graduate Program, King Mongkut's University of Technology Thonburi , Bangkok 10140 Thailand.|Theoretical and Computational Science Center (TaCS), Faculty of Science, King Mongkut's University of Technology Thonburi , Bangkok 10140 Thailand.|Faculty of Science, King Mongkut's University of Technology Thonburi , Bangkok 10140 Thailand.
authors.forename: Chan
authors.initials: C
authors.lastname: La-o-Vorakiat
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 637371 Singapore.
authors.forename: Huanxin
authors.initials: H
authors.lastname: Xia
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 637371 Singapore.|Laboratoire des Sciences Photomoléculaires, Ecole Polytechnique Fédérale de Lausanne , Switzerland.
authors.forename: Jeannette
authors.initials: J
authors.lastname: Kadro
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , 639798 Singapore.
authors.forename: Teddy
authors.initials: T
authors.lastname: Salim
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 637371 Singapore.
authors.forename: Daming
authors.initials: D
authors.lastname: Zhao
authors.affiliation: Theoretical Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Towfiq
authors.initials: T
authors.lastname: Ahmed
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , 639798 Singapore.
authors.forename: Yeng Ming
authors.initials: YM
authors.lastname: Lam
authors.affiliation: Theoretical Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.|Center for Integrated Nanotechnologies, Los Alamos National Laboratories , Los Alamos, New Mexico 87545, United States.
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Zhu
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 637371 Singapore.|Noyes Laboratory, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Rudolph A
authors.initials: RA
authors.lastname: Marcus
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 637371 Singapore.
authors.forename: Maria-Elisabeth
authors.initials: ME
authors.lastname: Michel-Beyerle
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 637371 Singapore.
authors.forename: Elbert E M
authors.initials: EE
authors.lastname: Chia
keywords: perovskite; phonon; solar cells; structural phase transition; terahertz time-domain spectroscopy; vibrational spectroscopy