Engineering ferroelectric instability to achieve ultralow thermal conductivity and high thermoelectric performance in Sn_1−xGe_xTe

Abstract

Tailoring local structural distortions and the associated ferroelectric instability in SnTe via Ge alloying resulted in ultralow lattice thermal conductivity which boosts zT to 1.6 at 721 K.

Promising and Eco‐Friendly Cu2X‐Based Thermoelectric Materials: Progress and Applications

“…Both Zhao et al and Liu et al have reported the peak zT value of SnSe can be higher than 2 when the temperature is above 800 K. Meanwhile, most other results suggest the peak zT values of SnSe are at the temperature range lower than 800 K . When the temperature is between ≈800 and ≈1000 K, Cu 2 X, PbX (X = Te, Se, and S), SnTe as well as low‐cost and stable BiCuSeO are more attractive. Through nonequilibrium processing, Tan et al have achieved a record‐high zT value of 2.5 in Pb 0.98 Na 0.02 Te‐8%SrTe at 923 K. As a potential substitution for highly toxic PbTe, peak zT values of SnTe of ≈1.5 have also been widely reported .…”

“…To secure high thermoelectric performance, high zT is required . As the temperature is generally limited by the application conditions or the employed material itself, the dominating factors for enhancing zT lie in enhancing S 2 σ, which is generally defined as the power factor to describe the electrical performance, as well as in reducing κ .…”

“…When the temperature is between ≈800 and ≈1000 K, Cu 2 X, PbX (X = Te, Se, and S), SnTe as well as low‐cost and stable BiCuSeO are more attractive. Through nonequilibrium processing, Tan et al have achieved a record‐high zT value of 2.5 in Pb 0.98 Na 0.02 Te‐8%SrTe at 923 K. As a potential substitution for highly toxic PbTe, peak zT values of SnTe of ≈1.5 have also been widely reported . More interestingly, multiple studies demonstrate that the peak zT values of superionic Cu 2 X‐based thermoelectric materials can be higher than 2 in the temperature range from ≈800 to ≈1000 K (mainly Cu 2 Se‐based ones) .…”

Intrinsically Low Thermal Conductivity and High Carrier Mobility in Dual Topological Quantum Material, n‐Type BiTe

“…[6][7][8][9] However,t hese extrinsic strategies also lead to charge carrier scattering, resulting in reduced charge carrier mobility (m). [10] Hence, identification of crystalline solids with intrinsically low k lat [10][11][12][13][14][15][16][17] or development of novel strategies to decrease k lat such as introduction of bonding hierarchy, [18,19] and ferroelectric instability [20] are important in designing high performance TE materials.…”

High‐Performance GeTe‐Based Thermoelectrics: from Materials to Devices

“…The minimization of thermal transport properties is mainly achieved through suppressing the electrical property‐independent κ l . [ 53–57 ] Thermoelectric materials with intrinsically low κ l usually have strong anharmonicity [ 58–60 ] (lone pair electrons lead to uneven distribution of the electron cloud, enhance asymmetry of crystal structure and subsequently induce strong anharmonicity) and weak chemical bond (which can lead to low sound velocity, v ). [ 61 ] To reduce κ l , hierarchical architecture engineering, [ 62–64 ] defect engineering (including point defects, [ 49,65,66 ] dislocations, [ 67 ] and dense grain boundaries [ 68,69 ] ) and other multi‐scale scattering centers [ 23,28,70 ] are introduced.…”