Valence band dispersion measurements of perovskite single crystals using angle-resolved photoemission spectroscopy.
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.
Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA. ygao@pas.rochester.edu.
Congcong
http://orcid.org/0000-0003-4556-577X
C
Wang
Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA. ygao@pas.rochester.edu.
Benjamin R
BR
Ecker
Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA.
Haotong
H
Wei
Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA.
Jinsong
J
Huang
Hunan Key Laboratory of Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan 410083, P. R. China.
Jian-Qiao
http://orcid.org/0000-0003-3168-9819
JQ
Meng
Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA. ygao@pas.rochester.edu.
Yongli
Y
Gao