Thermoelectric properties of p-type polycrystalline SnSe doped with Ag

Abstract

Many IV-VI semiconductors tend to be good thermoelectric materials, these include all Pb chalcogenides as well as Pb-free SnTe: all of which crystallize in a NaCl cubic structure. Another group of IV-VI compounds form layered orthorhombic structures. SnSe is one of these compounds, whose transport properties as a polycrystalline thermoelectric material have rarely been studied. Here we present our study of p-type polycrystalline SnSe doped with Ag, prepared by melting and hot pressing. SnSe has anisotropic properties with hysteresis observed in resistivity between 300 and 650 K regardless of doping. Ag is not an ideal dopant but is able to increase the carrier density significantly, as a result a peak zT of 0.6 was observed at 750 K. Transport properties of doped SnSe can be explained with a single parabolic band model, which suggests promising potential for this compound together with its challenges.

Understanding the electronic and phonon transport properties of a thermoelectric material BiCuSeO: a first-principles study

“…To understand why BiCuSeO has a relatively lower mobility as compared with other well-known thermoelectric materials [32][33][34][35][36], we show in Figure 3 . For comparison, we show in Fig.…”

Low thermal conductivity and triaxial phononic anisotropy of SnSe

“…It is therefore relatively safe to compare the thermal conductivity of a single crystal to those of polycrystalline samples with grain sizes on the order of 10 to 100 µm, such as those recently reported. 7 However, this comparison cannot be fully quantitative. One reason is due to our lack of a detailed description of grain boundaries in each particular experimental sample.…”

“…This is consistent with a thermoelectric figure of merit with a lower degree of anisotropy, as observed in polycrystals. 6,7 The information provided by our study will hopefully be useful for designing improved nanoengineering approaches to further optimize this promising thermoelectric.…”

“…5 using our κ brings it more in line with the largely isotropic values measured in polycrystals. 6,7 In conclusion, we have used a fully ab-initio method to study the lattice thermal conductivity of the Pnma phase of SnSe over a broad temperature range. We were motivated by three different sets of experimental results.…”

High-temperature thermoelectric properties of the β-As2−xBixTe3 solid solution

“…Of note, these values are significantly lower than those measured in Bi 2 Te 3 -based alloys but similar to those achieved in α-As 2 Te 3 or in other chalcogenides. 2,10,[22][23][24][25][26][27] In the parallel direction, κ L approaches the lowest limit of the thermal conductivity (Figure 2(c)) estimated using the model developed by Cahill and Pohl and the measured longitudinal and transverse sound velocities. 13,[28][29][30] Figure 2(d), which shows the variations in temperature of the ZT values, indicates that ZT increases with temperature for all samples.…”