Dataset on the electronic and thermal transport properties of quaternary compounds of (PbTe)0.95−x(PbSe)x(PbS)0.05

The data presented in this article are related to the research article entitled “High thermoelectric performance in pseudo quaternary compounds of (PbTe)0.95−x(PbSe)x(PbS)0.05 by simultaneous band convergence and nano precipitation” (Ginting et al., 2017) [1]. We measured electrical and thermal transport properties such as temperature-dependent Hall carrier density nH, Hall mobility μH, thermal diffusivity D, heat capacity Cp, and power factor S2σ in (PbTe)0.95−x(PbSe)x(PbS)0.05 (x=0.0, 0.05, 0.10, 0.15, 0.20, 0.35, and 0.95) compounds with other related compounds from references. From the theoretical fitting of thermal conductivity κ, we found that the temperature-dependent thermal conductivity follows nano-structure model as well as alloy scattering. Transmission electron microscopy images shows that there are numerous nano-scale precipitates in a matrix. Owing to the low thermal conductivity and high power factor, we report high thermoelectric performances such as the high ZT, engineering ZTeng, efficiency η.


Value of the data
The temperature-dependent Hall carrier density n H , Hall mobility μ H , thermal diffusivity D provides experimental understanding of the electrical and thermal transport properties on the compounds.
Comparison of thermoelectric properties such as temperature-dependent power factor S 2 σ, ZT values, engineering ZT values ZT eng , and efficiency with other related compounds gives the level of the thermoelectric performance.
Pisarenko plot of the Seebeck coefficient versus Hall carrier density shows that the compounds do not follow simple single parabolic band model.
The additional electrical-and thermal-transport properties and their thermoelectric performance for the compounds have an importance in more profound analysis of the measurements.

Data
The Hall carrier density n H and Hall mobility μ H are obtained from the isothermal Hall resistivity ρ xy (H) and electrical resistivity ρ measurements using the relations of R H ¼ ρ xy =H, n H ¼ À1=ðR H eÞ, and μ H ¼ 1=ðρneÞ, respectively. Seebeck coefficient is measured by thermoelectric measurement system (ZEM-3, ULVAC, Japan). TEM images (High Resolution images/STEM/ ED pattern) were collected using a JEOL 2100F at 200 kV. Energy dispersive x-ray spectrometer (EDS) analysis were obtained using Oxford Instruments (INCA platform) detector equipped on JEOM 2100F. Thermal diffusivity measurement is carried out by thermal conductivity measurement system (LFA-447, NETZSCH, Germany). Heat capacity is obtained from the Dulong-Petit fit using physical properties measurement system (PPMS Dynacool 14T, Quantum Design, USA).

Experimental design, materials and methods
The Table 1 presents the theoretical density, measured volumetric density, relative density, and specific heat of the compounds.  Table 1 Theoretical densities D T , measured volumetric densities D exp , relative densities D R , and specific heat C p at room temperature of the (PbTe) 0.95 À x (PbSe) x (PbS) 0.05 compounds. The measured volumetric densities D exp are all more than 96% of the theoretical densities D T , and the specific heat C p is increased with the increase of Se concentration, which is calculated by using the equation C p /k B per atom ¼ 3.07 þ4.7 Â 10 À 4 (T/K À300) by fitting experimental data.
Hall carrier concentrations n H of the compounds are decreased with increasing temperature as shown in Fig. 1(a). The Hall carrier concentration is not sensitive with Se concentration in the (PbTe) 0.95 À x (PbSe) x (PbS) 0.05 (x ¼0.1, 0.15, 0.2, and 0.35) compounds. Hall carrier mobilities are decreased with increasing Se concentration except x ¼0.35 case as presented in Fig. 1(b).
The Pisaranko plot in Fig. 3 shows that the experiment results are deviated from the single parabolic model, indicating that the Seebeck coefficient is influenced by two band (light-band and heavy band) model.
The thermal diffusivity in Fig. 4 is decreased with the increase of Se concentration. The thermal diffusivities are decreased with increasing temperature.
The lattice thermal conductivities, shown in Fig. 5(a), in this work are significantly lower than that calculated by using the alloy model of PbTe-PbSe-PbS and PbTe-PbSe, and it is also much reduced comparing with the previous reports by the nano-structuring as well as alloying scattering which is shown in Fig. 5(b).
Scanning Tunneling Electron Microscope (STEM) images in Fig. 6 show numerous nanoprecipitations with the size of 5-10 nm inside the sample of (PbTe) 0.75 (PbSe) 0.20 (PbS) 0.05 . Fig. 7 represents the thermoelectric figure-of-merit ZT values of the compounds and the other comparing materials as indicated from the references.