scholarly journals The role of excess Sn in Cu4Sn7S16 for modification of the band structure and a reduction in lattice thermal conductivity

2017 ◽  
Vol 5 (17) ◽  
pp. 4206-4213 ◽  
Author(s):  
Tongtong He ◽  
Naiming Lin ◽  
Zhengliang Du ◽  
Yimin Chao ◽  
Jiaolin Cui

In this work, we have investigated the band structures of ternary Cu4Sn7+xS16 (x = 0–1.0) compounds with an excess of Sn, and examined their thermoelectric (TE) properties.

2020 ◽  
Vol 10 (5) ◽  
pp. 602-609
Author(s):  
Adil H. Awad

Introduction: A new approach for expressing the lattice thermal conductivity of diatomic nanoscale materials is developed. Methods: The lattice thermal conductivity of two samples of GaAs nanobeam at 4-100K is calculated on the basis of monatomic dispersion relation. Phonons are scattered by nanobeam boundaries, point defects and other phonons via normal and Umklapp processes. Methods: A comparative study of the results of the present analysis and those obtained using Callaway formula is performed. We clearly demonstrate the importance of the utilised scattering mechanisms in lattice thermal conductivity by addressing the separate role of the phonon scattering relaxation rate. The formulas derived from the correction term are also presented, and their difference from Callaway model is evident. Furthermore their percentage contribution is sufficiently small to be neglected in calculating lattice thermal conductivity. Conclusion: Our model is successfully used to correlate the predicted lattice thermal conductivity with that of the experimental observation.


2017 ◽  
Vol 95 (4) ◽  
Author(s):  
Simen N. H. Eliassen ◽  
Ankita Katre ◽  
Georg K. H. Madsen ◽  
Clas Persson ◽  
Ole Martin Løvvik ◽  
...  

Author(s):  
Zhong-zhen Luo ◽  
Songting Cai ◽  
Shiqiang Hao ◽  
Trevor Bailey ◽  
Yubo Luo ◽  
...  

Although Ga doping can weaken the electron phonon coupling of n-type PbTe, Ga-doped PbTe has a relatively low carrier concentration (n) and high lattice thermal conductivity (κlat), resulting in a...


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Junsoo Park ◽  
Yi Xia ◽  
Vidvuds Ozoliņš ◽  
Anubhav Jain

AbstractUnderstanding how to optimize electronic band structures for thermoelectrics is a topic of long-standing interest in the community. Prior models have been limited to simplified bands and/or scattering models. In this study, we apply more rigorous scattering treatments to more realistic model band structures—upward-parabolic bands that inflect to an inverted-parabolic behavior—including cases of multiple bands. In contrast to common descriptors (e.g., quality factor and complexity factor), the degree to which multiple pockets improve thermoelectric performance is bounded by interband scattering and the relative shapes of the bands. We establish that extremely anisotropic “flat-and-dispersive” bands, although best-performing in theory, may not represent a promising design strategy in practice. Critically, we determine optimum bandwidth, dependent on temperature and lattice thermal conductivity, from perfect transport cutoffs that can in theory significantly boost zT beyond the values attainable through intrinsic band structures alone. Our analysis should be widely useful as the thermoelectric research community eyes zT > 3.


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