Constructing the Electronic Structure of CH3NH3PbI3 and CH3NH3PbBr3 Perovskite Thin Films from Single-Crystal Band Structure Measurements

Fengshuo Zu, Patrick Amsalem, David A. Egger, Rongbin Wang, Christian M. Wolff, Honghua Fang, Maria Antonietta Loi, Dieter Neher, Leeor Kronik, Steffen Duhm, Norbert Koch*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

34 Citations (Scopus)

Abstract

Photovoltaic cells based on halide perovskites, possessing remarkably high power conversion efficiencies have been reported. To push the development of such devices further, a comprehensive and reliable understanding of their electronic properties is essential but presently not available. To provide a solid foundation for understanding the electronic properties of polycrystalline thin films, we employ single-crystal band structure data from angle-resolved photoemission measurements. For two prototypical perovskites (CH3NH3PbBr3 and CH3NH3PbI3), we reveal the band dispersion in two high-symmetry directions and identify the global valence band maxima. With these benchmark data, we construct "standard" photoemission spectra from polycrystalline thin film samples and resolve challenges discussed in the literature for determining the valence band onset with high reliability. Within the framework laid out here, the consistency of relating the energy level alignment in perovskite-based photovoltaic and optoelectronic devices with their functional parameters is substantially enhanced.

Original languageEnglish
Pages (from-to)601-609
Number of pages17
JournalJOURNAL OF PHYSICAL CHEMISTRY LETTERS
Volume10
Issue number3
DOIs
Publication statusPublished - 7-Feb-2019

Keywords

  • METAL-HALIDE PEROVSKITES
  • ENERGY-LEVEL ALIGNMENT
  • SOLAR-CELLS
  • LEAD IODIDE
  • PHOTOEMISSION
  • 1ST-PRINCIPLES
  • MOBILITIES
  • EFFICIENT
  • VALENCE
  • BR

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