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Quasi-two-dimensional thermoelectricity in SnSe

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 نشر من قبل Thomas Szkopek
 تاريخ النشر 2018
  مجال البحث فيزياء
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Stannous selenide is a layered semiconductor that is a polar analogue of black phosphorus, and of great interest as a thermoelectric material. Unusually, hole doped SnSe supports a large Seebeck coefficient at high conductivity, which has not been explained to date. Angle resolved photo-emission spectroscopy, optical reflection spectroscopy and magnetotransport measurements reveal a multiple-valley valence band structure and a quasi two-dimensional dispersion, realizing a Hicks-Dresselhaus thermoelectric contributing to the high Seebeck coefficient at high carrier density. We further demonstrate that the hole accumulation layer in exfoliated SnSe transistors exhibits a field effect mobility of up to $250~mathrm{cm^2/Vs}$ at $T=1.3~mathrm{K}$. SnSe is thus found to be a high quality, quasi two-dimensional semiconductor ideal for thermoelectric applications.



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