Ultralow Lattice Thermal Conductivity in SnTe by Incorporating InSb

Abstract

Herein, a series of (Sn 1.06 Te) 1−x -(InSb) x (x = 0, 0.025, 0.05, 0.075) samples are fabricated, and their thermoelectric performances are studied. The all-scale structure defects containing the atomic-scale In doping defects, the nanoscale Sb precipitates, and the mesoscale grain boundary scatter phonons collectively in a wide range of frequencies to give the ultralow lattice thermal conductivity. Concurrently, the incorporation of InSb decreases carrier concentration with marginal loss in carrier mobility, resulting in a little variation of electrical properties over a wide temperature range. The significantly decreased thermal conductivity and the preserved high power factor lead to a maximum ZT value of ∼0.84 at 823 K in the (Sn 1.06 Te) 0.95 (InSb) 0.05 sample. This strategy of rapidly constructing all-scale structure defects could be applied to other thermoelectric systems to enhance thermoelectric performance. KEYWORDS: thermoelectric material, (Sn 1.06 Te) 1−x -(InSb) x , all-scale structure defects, ultralow lattice thermal conductivity, preserved high power factor

Substantial thermoelectric enhancement achieved by manipulating the band structure and dislocations in Ag and La co-doped SnTe

“…2(f) exhibits that the Ag/Sn atomic ratio is 2.72:1) rather than Ag 2 Te, though they were not detected by the XRD characterization, possibly due to its relatively low detection sensitivity. Suitable nanoscale impurity precipitates which induce lots of interfaces in matrix are expected to reduce the lattice thermal conductivity through blocking the transport of phonons [39].…”

“…On the other hand, ultralow lattice thermal conductivity could be realized by incorporating various microstructures, including dislocations [33,34], precipitates [35], mesoscale grain boundaries [36,37], and point defects [38]. For instance, the all-scale structure defects containing the atomic-scale In doping point defects, the nanoscale Sb precipitates, and the mesoscale grain boundaries substantially impede the phonon transport so that a minimum value of ~0.44 W•m -1 •K -1 is realized in (Sn 1.06 Te) 0.95 (InSb) 0.05 at 823 K, leading to a maximum zT value of ~0.84 [39]. Zheng et al [18] showed that Cu 2 Te acts as the source of interstitial defects to reduce the lattice thermal conductivity to the amorphous limit, achieving a high zT value (1.4 at 900 K).…”

Achieving Enhanced Thermoelectric Performance in (SnTe)1-x(Sb2Te3)x and (SnTe)1-y(Sb2Se3)y Synthesized via Solvothermal Reaction and Sintering

“…Thermoelectric properties were measured on the sintered samples from 300 to 813 K: a ZEM-3 (ULVAC) instrument was utilized to measure the electrical conductivity (σ) and Seebeck coefficient ( S ); an LFA 457 (Netzsch) instrument was applied to determine the thermal diffusivity ( D ). In addition, the specific heat capacity ( C p ) was estimated by the Dulong–Petit relationship C p = 3 R / M , where R and M are the universal gas constant and the molecular mass, respectively. The density (ρ) of pellets was calculated by using the respective mass and volume of each pellet.…”

A synergistic approach to achieving the high thermoelectric performance of La-doped SnTe using resonance state and partial band convergence

“…However, the large energy separation (ΔE=0.35 eV) [18][19][20] between the light and heavy holes inhibit the ∑ band to contribute to the transport properties at room temperature whereas, at high temperature, the L band moves toward the ∑ band, and thus there occurs the band convergence. [18][19][20][21][22][23] Pei et al have explained explicitly that in the two-valence band model of PbTe, the energy offset between conduction band (CB) and L-band of VB is temperaturedependent. However, the energy offset between CB and the heavy ∑ band of VB is independent of temperature but moves gradually with the addition of the dopants.…”