Direct observation of double valence-band extrema and anisotropic effective masses of the thermoelectric material SnSe

Synchrotron-based angle-resolved photoemission spectroscopy is used to determine the electronic structure of layered SnSe, which was recently turned out to be a potential thermoelectric material. We observe that the top of the valence band consists of two nearly independent hole bands, whose tops di...

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Bibliographic Details
Published inJapanese Journal of Applied Physics Vol. 57; no. 1; pp. 10301 - 10304
Main Authors Nagayama, Takanobu, Terashima, Kensei, Wakita, Takanori, Fujiwara, Hirokazu, Fukura, Tetsushi, Yano, Yuko, Ono, Kanta, Kumigashira, Hiroshi, Ogiso, Osamu, Yamashita, Aichi, Takano, Yoshihiko, Mori, Hitoshi, Usui, Hidetomo, Ochi, Masayuki, Kuroki, Kazuhiko, Muraoka, Yuji, Yokoya, Takayoshi
Format Journal Article
LanguageEnglish
Published Tokyo The Japan Society of Applied Physics 01.01.2018
Japanese Journal of Applied Physics
Subjects
Electron mass
Electronic structure
Electrons
Photoelectric emission
Thermoelectric materials
Thermoelectricity
Valence band
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Summary:Synchrotron-based angle-resolved photoemission spectroscopy is used to determine the electronic structure of layered SnSe, which was recently turned out to be a potential thermoelectric material. We observe that the top of the valence band consists of two nearly independent hole bands, whose tops differ by ∼20 meV in energy, indicating the necessity of a multivalley model to describe the thermoelectric properties. The estimated effective masses are anisotropic, with in-plane values of 0.16-0.39 m0 and an out-of-plane value of 0.71 m0, where m0 is the rest electron mass. Information of the electronic structure is essential to further enhance the thermoelectric performance of hole-doped SnSe.
ISSN:0021-4922
1347-4065
DOI:10.7567/JJAP.57.010301