摘要
InSb is a narrow-bandgap semiconductor with a zinc blende structure and has been wildly applied in photodetectors, infrared thermal imaging, and Hall devices. The facts of decent band structure, ultrahigh electron mobility,and nontoxic nature indicate that InSb may be a potential mid-temperature thermoelectric material. The critical challenges of InSb, such as high thermal conductivity and small Seebeck coefficient, have induced its ultrahigh lattice thermal conductivity, and thus low ZT values. In view of this, we have developed a competitive strategy typified by the cost-efficient nanocompositing of z wt% QSe_(2)(Q = Sn, W). Specifically, the Q_(In)^(+) and Se_(Sb)^(+) point defects were introduced in the In Sb system by nanocompositing the vested two-dimensional layered QSe_(2). In addition, the enlarged valence band maximum of intrinsic WSe_(2)acted as ladders can scatter a fair number of hole carriers, resulting in the relatively enhanced Seebeck coefficient of high temperature. Moreover, the disorderly distributed nanosheets/particles, and dislocations acting as obstacles can effectively delay the heat flow diffusion, inducing the strong scattering of thermal phonons. Consequently, an enhanced power factor of ~33.3 μW cm^(-1)K^(-2) and ZT value of~0.82 at 733 K have been achieved in the 3% WSe_(2)sample,companied with the engineering output power density ω_(max)~233 μW cm^(-1) and thermoelectric conversion efficiency η~5.2%. This artificially designed approach indicated by suited nanocompositing can integrate several engineering strategies such as point defects, nanoengineering, and energy filtering into one, providing a reference to optimize the thermoelectric performance of other thermoelectric systems.
InSb是一种具有闪锌矿结构的窄带隙半导体,在光电探测器、红外热成像、霍尔器件等领域有着广泛的应用.良好的能带结构、超高的电子迁移率和无毒性质表明InSb可能是一种潜在的中温热电材料.InSb当前面临着一些关键挑战,如高导热系数和小Seebeck系数,导致其超高的晶格导热系数,进而低的ZT值.鉴于此,我们发展了一种z wt%QSe_(2)(Q=Sn,W)纳米复合的高效策略,即通过对二维层状QSe_(2)的纳米复合,在InSb体系中引入Q_(In)^(+)和Se_(Sb)^(+)点缺陷.此外,本征WSe_(2)的价带作为势垒可以散射相当数量的空穴载流子,导致本征激发阶段的Seebeck系数升高.此外,无序分布的纳米片/粒子和位错可以有效地阻碍热流扩散,形成热声子的强散射.结果表明,3%WSe_(2)样品的功率因子提高到~33.3μW cm^(-1)K^(-2),733 K时ZT值提高到~0.82,工程输出功率密度ω_(max)~233μW cm^(-1),工程热电转换效率η~5.2%.
作者
Jiwu Xin
Wang Li
Sihui Li
Yang Tao
Tian Xu
Yubo Luo
Qinghui Jiang
Lei Wei
Junyou Yang
辛集武;李旺;李思慧;陶阳;许天;罗裕波;姜庆辉;魏磊;杨君友(State Key Laboratory of Materials Processing and Die and Mould Technology,Huazhong University of Science and Technology,Wuhan 430074,China;School of Electrical and Electronic Engineering,Nanyang Technological University,50 Nanyang Avenue,Singapore 639798,Singapore)
基金
supported by the National Natural Science Foundation of China (92163211 and 51872102)
Foshan (Southern China) Institute for New Materials (2021AYF25005)
Singapore Ministry of Education Academic Research Fund Tier 2 (MOE2019-T2-2-127 and MOET2EP50120-0002)
the A*STAR under AME IRG (A2083c0062)
Singapore Ministry of Education Academic Research Fund Tier 1 (RG90/19 and RG73/ 19)
Singapore National Research Foundation Competitive Research Program (NRF-CRP18-2017-02)。
