Accessing the Conduction Band Dispersion in CH3NH3PbI3 Single Crystals

Jinpeng Yang; Haruki Sato; Hibiki Orio; Xianjie Liu; Mats Fahlman; Nobuo Ueno; Hiroyuki Yoshida; Takashi Yamada; Satoshi Kera

doi:10.1021/acs.jpclett.1c00530

Accessing the Conduction Band Dispersion in CH₃NH₃PbI₃ Single Crystals

J Phys Chem Lett. 2021 Apr 22;12(15):3773-3778. doi: 10.1021/acs.jpclett.1c00530. Epub 2021 Apr 12.

Authors

Jinpeng Yang^{1

2}, Haruki Sato³, Hibiki Orio³, Xianjie Liu⁴, Mats Fahlman⁴, Nobuo Ueno⁵, Hiroyuki Yoshida^{6

7}, Takashi Yamada⁸, Satoshi Kera²

Affiliations

¹ College of Physical Science and Technology, Yangzhou University, Jiangsu, China.
² Department of Photo-Molecular Science, Institute for Molecular Science, Myodaiji, Okazaki, Japan.
³ Graduate School of Science and Engineering, Chiba University, Chiba, Japan.
⁴ Laboratory for Organic Electronics, ITN, Linköping University, Norrköping, Sweden.
⁵ Graduate School of Advanced Integration Science, Chiba University, Chiba, Japan.
⁶ Graduate School of Engineering, Chiba University, Chiba, Japan.
⁷ Molecular Chirality Research Center, Chiba University, Chiba, Japan.
⁸ Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Japan.

PMID: 33844910
DOI: 10.1021/acs.jpclett.1c00530

Abstract

The conduction band dispersion in methylammonium lead iodide (CH₃NH₃PbI₃) was studied by both angle-resolved two-photon photoelectron spectroscopy (AR-2PPE) with low photon intensity (∼0.0125 nJ/pulse) and angle-resolved low-energy inverse photoelectron spectroscopy (AR-LEIPS). Clear energy dispersion of the conduction band along the Γ-M direction was first observed by these independent methods under different temperatures, and the dispersion was found to be consistent with band calculation under the cubic phase. The effective mass of the electrons at the Γ point was estimated to be (0.20 ± 0.05)m₀ at the temperature of 90 K. The observed conduction band energy was different between the AR-LEIPS and AR-2PPE, which was ascribed to the electronic-correlation-dependent difference of initial and final states probing processes. The present results also indicate that the surface structure in CH₃NH₃PbI₃ provides the cubic-dominated electronic property even at lower temperatures.