Enhanced thermoelectric performance of PbSe-graphene nanocomposite manufactured with acoustic cavitation induced defects

Structural modulation and resonant level enable high thermoelectric performance of GeTe in the mid-to-low temperature range

“…Previous strategies have been proved to achieve higher zTs, such as tuning the carrier concentration to an optimal level, [7][8][9][10] band structure engineering to enhance the power factor S 2 s by promoting band convergence [11][12][13][14][15] or inducing a resonant level, [16][17][18][19] and phonon engineering to suppress the lattice thermal conductivity. [20][21][22][23] PbTe has long been considered as the most excellent TE candidate in the mid-temperature range, but the toxicity of Pb limits its broader application. Because of the environmental friendliness and mechanical robustness, the emerging GeTe is a promising alternative to PbTe.…”

“…Previous strategies have been proved to achieve higher zT s, such as tuning the carrier concentration to an optimal level, 7–10 band structure engineering to enhance the power factor S 2 σ by promoting band convergence 11–15 or inducing a resonant level, 16–19 and phonon engineering to suppress the lattice thermal conductivity. 20–23…”

Phonon interference effects in graphene nanomesh

“…电能量转换 [1,2] 、蒸汽检测 [3,4] 、热能存储 [5] 、场效应晶体管 [6] 等领域具有广阔的 应用前景。尤其是 GNM 周期纳米孔的引入使电子和声子输运解耦，在保持电 子通道的同时有效地散射声子，提供了一种独立操纵导热系数的方法。因此， 其导热性能的研究引起了越来越多的关注 [7][8][9] 。 调控石墨烯的导热系数的方法通常有两种，一种方法是利用声子的非相干 特性，通过引入粗糙界面 [10][11][12] 、杂质 [13,14] 和表面缺陷 [15,16] 等降低声子的平均自 由程。另一种方法则是利用声子的相干特性，通过引入二次人工周期，如超晶 格、纳米孔等诱发声子干涉效应 [17,18] 。声子干涉可引起声子谱的布里渊区折叠 [19] 、声子局部化 [20,21] 和声子约束 [22] 等多种波动效应，是抑制 GNM 热输运的有 效途径。因此，人们对 GNM 中的声子干涉效应进行了一系列研究，如 Cui 等 人 [23] 结合分子动力学模拟和第一性原理计算，发现布里渊区折叠引起的带隙变 宽和声子群速度降低导致了 GNM 的导热系数较石墨烯明显降低。Hu 等人 [24] 采 用了非平衡分子动力学和波包动力学模拟对相干声子的局域化进行了研究，发 现纳米孔的随机分布可以诱导相干声子在孔洞周围的局部化，导致了导热系数 的降低；同时 Yang 等人 [25] 研究发现孔隙率的增加和周期长度的减小将大大降 低 GNM 的导热系数，他们将其归因于声子局域化，通过纳米网和石墨烯导热 系数比值的变化，定量地表明 GNM 中 Umklapp 散射可用的状态更多。Wang 等 人 [26] 本次研究均是基于 LAMMPS 软件进行的 [27] 。在 NEMD 模拟中，我们采用 Kinaci 等人 [28] 优化后的 Tersoff 势函数以更准确地描述 GNM 的物质特性和原子 键相互作用力。同时原子运动积分步长设置为 0.…”

Effect of MXene Addition on the Thermoelectric and Mechanical Properties of Skutterudite CoSb3

“…Both electrons and phonons contribute to the thermal conductivity. The lattice part of thermal conductivity can be reduced by providing more phonon scattering centers, which can be created using complex crystal geometry, − grain boundary engineering, and forming nanocomposites. − Introducing nanoinclusion to enhance phonon scattering centers is a novel approach to reducing the thermal conductivity of the system. Especially, incorporating conducting carbon-based materials within the matrix of thermoelectric materials such as doped SrTiO 3 , ,− Bi 2 Te 3 , − and skutterudite − positively impacted their thermoelectric performances.…”