中文版 | English
CSpace
MXene as charge reservoir promotes the thermoelectric performance of layered metal selenide SnSe2
Wei, Yiqing1,2; Zhou, Zizhen1,2; Liu, Jie3; Zhang, Bin3; Wang, Guiwen3; Han, Guang4; Wang, Guoyu5; Zhou, Xiaoyuan1,2,3; Lu, Xu1,2
2022-12-01
摘要Layered metal selenides have attracted widespread attention in thermoelectrics. However, the thermo-electric performance of these compounds holding n-type conduction suffers from low electrical con-ductivity especially along out-of-plane direction mainly due to the carrier deficiency. Herein, two-dimensional MXene with metallic conductivity is introduced into SnSe2 matrix as a carrier reservoir to alleviate the electron shortage. Br-doped SnSe2 /Ti3C2Tx composites are successfully fabricated by a hy-drothermal method combined with solid-state synthesis. Compared with that of pristine SnSe2, the car-rier concentration of SnSe1.97Br0.03 /0.4 wt% Ti3C2Tx is enlarged by three orders of magnitude from 10 17 cm-3 to 10 20 cm-3. Meanwhile, it is revealed that the electrons transfer from the MXene layers into the SnSe2 matrix facilitated by elevated temperature based on the first-principles calculations. Combining with the intrinsically low lattice thermal conductivity, a peak zT close to unity is achieved along out-of -plane direction at 818 K in SnSe1.97Br0.03 /0.4 wt% Ti3C2Tx sample. These findings offer an available strategy to efficiently increase the carrier concentration of wide-gap layered compounds.(c) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
关键词Thermoelectrics SnSe 2-based composites MXene Work function Carrier supplier
DOI10.1016/j.actamat.2022.118369
发表期刊ACTA MATERIALIA
ISSN1359-6454
卷号241页码:9
通讯作者Zhou, Xiaoyuan(xiaoyuan2013@cqu.edu.cn) ; Lu, Xu(luxu@cqu.edu.cn)
收录类别SCI
WOS记录号WOS:000867453200005
语种英语