All-scale Architecturing of Microstructure in Chalcogenide Thermoelectric Materials

Cai, Songting; Luo, Yubo; Hu, Xiaobing; Kanatzidis, Mercouri G.; Dravid, Vinayak P.

doi:10.1017/s1431927619011917

Cited by 1 publication

(1 citation statement)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To optimize the thermoelectric performance, on one hand, enhancement of the power factor (PF = S 2 σ) through band structure engineering (including dopant engineering, − band convergence, − band flattening and resonant state induction for effective mass increase, ,− or texturing for carrier mobility improvement) has been widely applied in a variety of well-known narrow band gap semiconductors such as lead chalcogenides, − I–V–VI 2 compounds (I = Cu, Ag, Au, or alkali metal; V = As, Sb, or Bi; VI = Se or Te), , Bi 2 Te 3, lead antimony silver telluride (LAST) and skutterudite . On the other hand, low lattice thermal conductivity could be obtained by either architecture engineering at all length scales ,,,− or in special materials with a high degree of structural complexity. − SnSe is a good example for the latter, where the large lattice anharmonicity and complex layered crystal structure play significant roles in its ultralow intrinsic thermal conductivity. ,,− …”

Section: Introductionmentioning

confidence: 99%

Ultralow Thermal Conductivity and Thermoelectric Properties of Rb₂Bi₈Se₁₃

et al. 2020

Self Cite

View full text Add to dashboard Cite

Complex bismuth chalcogenides are narrow band gap semiconductors with intrinsic low thermal conductivity, which exhibit high potential as highly efficient thermoelectric materials. Here, we assess the basic thermoelectric properties of polycrystalline Rb2Bi8Se13 in the temperature range 300–823 K as well as performance-optimizing strategies. We find that the as-made bulk samples are single phase with the monoclinic crystal structure (P21/m) and crystallize in layer morphology. The pristine sample exhibits an exceedingly low lattice thermal conductivity of 0.6–0.46 W·m–1·K–1 at 300–823 K, which derives from strong lattice anharmonicity, large Grüneisen parameters, and low phonon velocities induced by the complex crystal structure with heavy atom Bi and a large unit cell. The Cl doping successfully enhances the carrier concentration in Rb2Bi8Se13 with a negligible impact on the electronic band structure, displaying common doping behaviors. Se vacancy, on the contrary, leads to n-type doping and enhances the effective mass and power factors more significantly. Consequently, a maximum ZT of ∼0.75 at 823 K for the 0.3% Se-vacancy-doped sample is obtained.

show abstract