当前位置：
X-MOL 学术
›
ACS Appl. Mater. Interfaces
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Tailoring Nanoporous Structures in Bi2Te3 Thin Films for Improved Thermoelectric Performance
ACS Applied Materials & Interfaces ( IF 8.3 ) Pub Date : 2019-10-03 , DOI: 10.1021/acsami.9b13920 Jixiang Qiao 1, 2 , Yang Zhao 1, 2 , Qun Jin 1, 3 , Jun Tan 1 , Siqing Kang 1 , Jianhang Qiu 1 , Kaiping Tai 1
ACS Applied Materials & Interfaces ( IF 8.3 ) Pub Date : 2019-10-03 , DOI: 10.1021/acsami.9b13920 Jixiang Qiao 1, 2 , Yang Zhao 1, 2 , Qun Jin 1, 3 , Jun Tan 1 , Siqing Kang 1 , Jianhang Qiu 1 , Kaiping Tai 1
Affiliation
|
Thin-film thermoelectrics (TEs) with unique advantages have triggered great interest in thermal management and energy harvesting technology for ambient temperature microscale systems. Although they have exhibited a good prospect, their unsatisfactory performances still seriously hamper their widespread application. Tailoring the porous structure has been demonstrated to be a facile strategy to significantly reduce thermal conductivity and enhance the figure of merit (ZT) of bulk TE materials; however, it is challenging for thin-film TEs. Here, the nanoporous Bi2Te3 thin films with faceted pore shapes and various porosities, pore sizes, and pore intervals are carefully designed and fabricated by evacuating the over-stoichiometry Te atoms. The dependence of the carrier mobility and lattice thermal conductivity on the pore characteristics is investigated. In the case of the pore interval longer than the electron mean free path, the porous structure greatly reduces the lattice thermal conductivity without affecting the electrical conductivity obviously. Phonon specular backscattering that is highly related to the pore characteristics is suggested to be mainly responsible for thermal conductivity reduction, resulting in ∼60% enhancement in ZT at room temperature, that is, from ∼0.42 for the dense film to ∼0.67 for the nanoporous film. The enhanced ZT value is comparable to that of commercial bulk TEs and can be further improved by optimizing the carrier concentrations. This work provides a general approach to fabricate high-performance chalcogenide TE thin-film materials.
中文翻译：
在Bi 2 Te 3薄膜中定制纳米孔结构以改善热电性能
具有独特优势的薄膜热电（TE）引起了人们对环境温度微型系统的热管理和能量收集技术的极大兴趣。尽管它们显示出良好的前景，但它们的不令人满意的性能仍然严重阻碍了它们的广泛应用。定制多孔结构是一种可行的策略，可以显着降低导热系数并提高块状TE材料的品质因数（ZT）。但是，对于薄膜TE来说，这是一个挑战。在这里，纳米孔Bi 2 Te 3通过排空化学计量过高的Te原子，精心设计和制造具有多面孔形状和各种孔隙度，孔径和孔间隔的薄膜。研究了载流子迁移率和晶格热导率对孔特性的依赖性。在孔间隔长于电子平均自由程的情况下，多孔结构大大降低了晶格导热率，而没有明显影响导电率。与声子特性高度相关的声子镜面反向散射被认为是导致热导率降低的主要原因，室温下ZT增强了〜60％，即从致密膜的〜0.42到纳米孔的〜0.67。电影。增强版ZT该值可与商用散装TE相比，并且可以通过优化载流子浓度来进一步提高。这项工作为制造高性能硫族化物TE薄膜材料提供了一种通用方法。
更新日期：2019-10-03
中文翻译：
在Bi 2 Te 3薄膜中定制纳米孔结构以改善热电性能
具有独特优势的薄膜热电（TE）引起了人们对环境温度微型系统的热管理和能量收集技术的极大兴趣。尽管它们显示出良好的前景，但它们的不令人满意的性能仍然严重阻碍了它们的广泛应用。定制多孔结构是一种可行的策略，可以显着降低导热系数并提高块状TE材料的品质因数（ZT）。但是，对于薄膜TE来说，这是一个挑战。在这里，纳米孔Bi 2 Te 3通过排空化学计量过高的Te原子，精心设计和制造具有多面孔形状和各种孔隙度，孔径和孔间隔的薄膜。研究了载流子迁移率和晶格热导率对孔特性的依赖性。在孔间隔长于电子平均自由程的情况下，多孔结构大大降低了晶格导热率，而没有明显影响导电率。与声子特性高度相关的声子镜面反向散射被认为是导致热导率降低的主要原因，室温下ZT增强了〜60％，即从致密膜的〜0.42到纳米孔的〜0.67。电影。增强版ZT该值可与商用散装TE相比，并且可以通过优化载流子浓度来进一步提高。这项工作为制造高性能硫族化物TE薄膜材料提供了一种通用方法。
京公网安备 11010802027423号