Analyzing transport properties of p-type Mg₂Si–Mg₂Sn solid solutions: optimization of thermoelectric performance and insight into the electronic band structure

Abstract

Figure of merit zT mapping of p-Mg2Si1−xSnx with respect to carrier concentration.

Discrepancy between Constant Properties Model and Temperature-Dependent Material Properties for Performance Estimation of Thermoelectric Generators

“…Since a generalized temperature dependence study for all types of dependence is quite elaborate, a comparative study based on seven well-known and representative TE materials [ 20 , 21 , 22 , 23 , 24 ] was conducted. To understand the role of the dependence of each of , and in performance estimation, the calculated maximum efficiencies when all properties are considered as dependent (referred to as “real case” or “exact” from now on) were compared with the calculated efficiencies of model materials.…”

“…Since SnSe has much higher resistivity, the scale for it is given on the right y-axis. All the raw experimental data taken from the literature [ 20 , 21 , 22 , 23 , 24 ] were fitted with appropriate polynomials (usually 3rd or 4th order). For SnSe, a 9th order polynomial fit was used owing to the complex T dependence and hence shows an unusually high max .…”

Unveiling the Correlation between the Crystalline Structure of M‐Filled CoSb3 (M = Y, K, Sr) Skutterudites and Their Thermoelectric Transport Properties

“…Consequently, the strategies addressing a modification of the band structure, known as band engineering, have been deeply investigated regarding thermoelectric efficiency. [8][9][10][11][12] Among them, band convergence has resulted in noteworthy improvements of the electrical properties, as in PbTe [13][14][15] and Mg 2 Si [16][17][18] systems. These changes in the electronic bands have been analyzed in terms of the crystallographic structure.…”

Systematic analysis of the interplay between synthesis route, microstructure, and thermoelectric performance in p-type Mg2Si0.2Sn0.8

“…Among several thermoelectric materials, magnesium silicide based solid solutions are highly promising for thermoelectric applications in the middle temperature range (300-800 K) due to materials abundance, non-toxicity, low density and cost, good environmental compatibility, and high thermoelectric performance for n-type ( ≈ 1.4) [8,14,[22][23][24]. Compared to ntype Mg 2 (Si,Sn), p-type Mg 2 (Si,Sn) has inferior properties ( ≈ 0.6) and further optimization is highly desirable for a practical implementation of Mg 2 Si-based thermoelectric generators [25][26][27][28][29][30][31][32]. Both p-and n-type Mg 2 (Si,Sn) are synthesized using different synthesis techniques including high energy ball milling (BM) [14,32], or melt spinning combined with (spark plasma) sintering [25,26,29,30,33,34].…”

“…Using the well-established single parabolic band (SPB) model, we have systematically investigated the differences of Li-doped Mg 2 Si 0.2 Sn 0.8 fabricated by two popular synthesis routes: high energy ball milling (BM) and induction melting (IM) [14,18,42]. The composition was chosen because Li is the most efficient dopant for p-type Mg 2 Si 1-x Sn x and the samples with x = 0.8 have similar efficiency as the samples with x = 0.6 but a higher power factor [32,43]; they are also further outside the reported miscibility gap which is important for long term stability [44][45][46]. Generally, for both n-and p-type Mg 2 (Si,Sn) relatively large differences in performance are reported from different experimental studies [30,43] making this class a suitable candidate for a systematic comparison of synthesis techniques.…”