Premium
Gate‐Tunable Polar Optical Phonon to Piezoelectric Scattering in Few‐Layer Bi 2 O 2 Se for High‐Performance Thermoelectrics
Author(s) -
Yang Fang,
Wu Jing,
Suwardi Ady,
Zhao Yunshan,
Liang Boyuan,
Jiang Jie,
Xu Jianwei,
Chi Dongzhi,
Hippalgaonkar Kedar,
Lu Junpeng,
Ni Zhenhua
Publication year - 2021
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.202004786
Subject(s) - materials science , thermoelectric materials , phonon scattering , scattering , thermoelectric effect , electron mobility , phonon , optoelectronics , piezoelectricity , atmospheric temperature range , carrier scattering , condensed matter physics , thermal conductivity , optics , composite material , physics , thermodynamics
Atomically thin Bi 2 O 2 Se has emerged as a new member in 2D materials with ultrahigh carrier mobility and excellent air‐stability, showing great potential for electronics and optoelectronics. In addition, its ferroelectric nature renders an ultralow thermal conductivity, making it a perfect candidate for thermoelectrics. In this work, the thermoelectric performance of 2D Bi 2 O 2 Se is investigated over a wide temperature range (20–300 K). A gate‐tunable transition from polar optical phonon (POP) scattering to piezoelectric scattering is observed, which facilitates the capacity of drastic mobility engineering in 2D Bi 2 O 2 Se. Consequently, a high power factor of more than 400 µ W m −1 K −2 over an unprecedented temperature range (80–200 K) is achieved, corresponding to the persistently high mobility arising from the highly gate‐tunable scattering mechanism. This finding provides a new avenue for maximizing thermoelectric performance by changing the scattering mechanism and carrier mobility over a wide temperature range.