Lattice dynamics and vibrational spectra of the orthorhombic, tetragonal, and cubic phases of methylammonium lead iodide

The hybrid halide perovskite ${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}{\mathrm{PbI}}_{3}$ exhibits a complex structural behavior, with successive transitions between orthorhombic, tetragonal, and cubic polymorphs around 165 and 327 K. Herein we report first-principles lattice dynamics (phonon spectrum) for each phase of ${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}{\mathrm{PbI}}_{3}$. The equilibrium structures compare well to solutions of temperature-dependent powder neutron diffraction. By following the normal modes, we calculate infrared and Raman intensities of the vibrations, and compare them to the measurement of a single crystal where the Raman laser is controlled to avoid degradation of the sample. Despite a clear…

• RS
  Royal Society

  Awards: 277757, EP/L000202
• UO
  University of Bath

  Award: EP/K004956/1
• MD
  Ministerio de Economía y Competitividad

  Awards: MAT2012-37776, CSD2010-00044
• OO
  Office of Science
• EA
  Engineering and Physical Sciences Research Council

  Awards: EP/M014797/1, L000202, EP/K004956/1, EP/J002305/1, EP/M009580/1, EP/K004956/1, EP/M023532/1, EP/K016288/1, Grant No. EP/L000202, EP/K004956, EP/L000202, EP/M009580/1, EP/ G03768X/1, EP/J002305/1, EP/K016288/1, EP/K016288, EP/M014797/1
• ER
  European Research Council

  Award: 277757
• SF
  Seventh Framework Programme

  Award: 316494