On the role of the electron-phonon interaction in the temperature dependence of the gap of lead halide perovskites

Abstract

Lead halide perovskites are causing a change of paradigm in photovoltaics. Among other peculiarities, these perovskites exhibit an atypical temperature dependence of the fundamental optical gap: It decreases in energy with decreasing temperature. So far reports ascribe such a behavior to a particularly strong electron-phonon renormalization of the band gap, neglecting completely contributions from thermal expansion effects. However, high pressure experiments performed, for instance, on the archetypal perovskite MAPbI${}_3$, where MA stands for methylammonium, yield a negative pressure coefficient for the gap of the tetragonal room-temperature phase, which speaks against the assumption of a negligible gap shift due to thermal expansion. On the basis of the high pressure results, we show here that for MAPbI${}_3$ the temperature-induced gap renormalization due to electron-phonon interaction can only account for about 40\% of the total energy shift, thus implying thermal expansion to be the dominant term. Furthermore, this result possesses general validity, holding also for the tetragonal or cubic phase, stable at ambient conditions, of other halide perovskite counterparts.

arXiv comment24 pages (manuscript 17 pages + supplementary information 7 pages), 5 figures (manuscript 4 figures + supplementary information 1 figure), submitted to J. Phys. Chem. Lett

References in corpus (9)

• Atomistic origins of high-performance in hybrid halide perovskite solar cells
• Relativistic Solar Cells
• Lattice dynamics and vibrational spectra of the orthorhombic, tetragonal and cubic phases of methylammonium lead iodide
• Dynamic disorder, phonon lifetimes, and the assignment of modes to the vibrational spectra of methylammonium lead halide perovskites
• Phonon anharmonicity, lifetimes and thermal transport in CH${}_3$NH${}_3$PbI${}_3$ from many-body perturbation theory
• Electron-Phonon Interaction in Tetrahedral Semiconductors
• Perspective: Theory and simulation of hybrid halide perovskites
• Temperature Dependence of the Energy Levels of Methylammonium Lead Iodide Perovskite from First Principles
• Electron-phonon renormalization of the absorption edge of the cuprous halides

Cited by in corpus (7)

• Revealing unusual bandgap shifts with temperature and bandgap renormalization effect in phase-stabilized metal halide perovskite thin films
• Using Pressure to Unravel the Structure-Dynamic-Disorder Relationship in Metal Halide Perovskites
• Description of Excitonic Absorption Using the Sommerfeld Enhancement Factor and Band-Fluctuations
• Thermal fluctuations and carrier localization induced by dynamic disorder in MAPbI3 described by a first-principles based tight-binding model
• Determining Exciton Binding Energy and Reduced Effective Mass in Metal Tri-Halide Perovskites from Optical and Impedance Spectroscopy Measurements
• Sign of the Gap Temperature Dependence in CsPb(Br,Cl)3 Nanocrystals Determined by Cs-Rattler Mediated Electron-Phonon Coupling
• Absence of Anomalous Electron-Phonon Coupling in the Temperature Renormalization of the Gap of CsPbBr${}_3$ Nanocrystals