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Enhanced Thermoelectric Performance of Ultrathin Bi 2 Se 3 Nanosheets through Thickness Control
Author(s) -
Hong Min,
Chen ZhiGang,
Yang Lei,
Han Guang,
Zou Jin
Publication year - 2015
Publication title -
advanced electronic materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.25
H-Index - 56
ISSN - 2199-160X
DOI - 10.1002/aelm.201500025
Subject(s) - materials science , thermoelectric effect , seebeck coefficient , thermal conductivity , band gap , thermoelectric materials , electrical resistivity and conductivity , nanotechnology , optoelectronics , composite material , electrical engineering , physics , thermodynamics , engineering
Large‐scale Bi 2 Se 3 nanosheets with controllable thickness have been synthesized by a microwave‐assisted solvothermal method. Through detailed structural characterizations, high‐quality Bi 2 Se 3 nanosheets with average thickness of 1, 4, 7, and 13 nm have been fabricated. Their thermoelectric performance has been detailed investigated by experiments and fundamental nonparabolic Kane models. A significantly reduced thermal conductivity (only 0.41 W m ‐1 K ‐1 ), and enhanced powder factor (4.71 × 10 ‐4 W m ‐1 K ‐2 with a Seebeck coefficient of –155.32 μV K ‐1 and an electrical conductivity of 1.96 × 10 4 S m ‐1 ) are observed in the pellet composed of single‐layered Bi 2 Se 3 nanosheets. Such an enhanced thermoelectric performance is ascribed to the broadened bandgap and optimized Fermi level in ultrathin Bi 2 Se 3 nanosheets.