Valence band dispersion measurements of perovskite single crystals using angle-resolved photoemission spectroscopy

Congcong Wang; Benjamin R Ecker; Haotong Wei; Jinsong Huang; Jian-Qiao Meng; Yongli Gao

doi:10.1039/c6cp07176g

Valence band dispersion measurements of perovskite single crystals using angle-resolved photoemission spectroscopy

Phys Chem Chem Phys. 2017 Feb 15;19(7):5361-5365. doi: 10.1039/c6cp07176g.

Authors

Congcong Wang¹, Benjamin R Ecker¹, Haotong Wei², Jinsong Huang², Jian-Qiao Meng³, Yongli Gao¹

Affiliations

¹ Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA. ygao@pas.rochester.edu.
² Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA.
³ Hunan Key Laboratory of Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan 410083, P. R. China.

PMID: 28155943
DOI: 10.1039/c6cp07176g

Abstract

The electronic structure of a cleaved perovskite (CH₃NH₃PbBr₃) single crystal was studied in an ultra-high vacuum (UHV) system using angle-resolved photoemission spectroscopy (ARPES) and inverse photoelectron spectroscopy (IPES). Highly reproducible dispersive features of the valence bands were observed with symmetry about the Brillouin zone center and boundaries. The largest dispersion width was found to be ∼0.73 eV and ∼0.98 eV along the ΓX and ΓM directions, respectively. The effective mass of the holes was estimated to be ∼0.59m₀. The quality of the surface was verified using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The elemental composition was investigated using high resolution X-ray photoelectron spectroscopy (XPS). The experimental electronic structure shows a good agreement with the theoretical calculation.