TY - JOUR
T1 - Direct observation of double valence-band extrema and anisotropic effective masses of the thermoelectric material SnSe
AU - Nagayama, Takanobu
AU - Terashima, Kensei
AU - Wakita, Takanori
AU - Fujiwara, Hirokazu
AU - Fukura, Tetsushi
AU - Yano, Yuko
AU - Ono, Kanta
AU - Kumigashira, Hiroshi
AU - Ogiso, Osamu
AU - Yamashita, Aichi
AU - Takano, Yoshihiko
AU - Mori, Hitoshi
AU - Usui, Hidetomo
AU - Ochi, Masayuki
AU - Kuroki, Kazuhiko
AU - Muraoka, Yuji
AU - Yokoya, Takayoshi
N1 - Funding Information:
Acknowledgments H.F. is supported by a Grant-in-Aid for JSPS Fellows. This work was performed under the approval of the Photon Factory Program Advisory Committee (Proposal Nos. 2016G157, 2016G158, and 2016G667). This work was partially supported by JSPS KAKENHI Grant Numbers 15H03691 and 16H04493 and by JST CREST (No. JPMJCR16Q6), Japan. This work was also partially supported by the Program for Promoting the Enhancement of Research Universities from MEXT.
Publisher Copyright:
© 2018 The Japan Society of Applied Physics.
PY - 2018/1
Y1 - 2018/1
N2 - 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 m 0 and an out-of-plane value of 0.71 m 0, where m 0 is the rest electron mass. Information of the electronic structure is essential to further enhance the thermoelectric performance of hole-doped SnSe.
AB - 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 m 0 and an out-of-plane value of 0.71 m 0, where m 0 is the rest electron mass. Information of the electronic structure is essential to further enhance the thermoelectric performance of hole-doped SnSe.
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U2 - 10.7567/JJAP.57.010301
DO - 10.7567/JJAP.57.010301
M3 - Article
AN - SCOPUS:85040378179
SN - 0021-4922
VL - 57
JO - Japanese Journal of Applied Physics
JF - Japanese Journal of Applied Physics
IS - 1
M1 - 010301
ER -