Incompletely Decomposed In₄SnSe₄ Leads to High‐Ranged Thermoelectric Performance in n‐Type PbTe

Abstract

Additives in thermoelectric materials are conventionally considered as either extrinsic defects or second phases regardless of their dynamic processes. Herein, In4SnSe4, with inherent low thermal conductivity, is introduced into n‐type PbTe. It is revealed that In4SnSe4 decomposes incompletely at high temperatures, in which around 80% of In4SnSe4 dissolves into InSe and Sn, while 20% forms as nano‐precipitates. Benefiting from the incomplete decomposition, PbTe‐0.1%In4SnSe4 presents superior thermoelectric performance compared to the stepwise and compositionally identical PbTe‐0.4%InSe‐0.1%Sn. The residual In4SnSe4 along with Sn and InSe jointly contribute to the synergetic optimization of carrier mobility and lattice thermal conductivity in PbTe‐0.1%In4SnSe4. As a result, the room‐temperature dimensionless figure of merit (ZT) of ≈0.4 and the ZTave of ≈0.83 at 300–573 K are obtained, and an experimental maximum thermoelectric conversion efficiency (η) of ≈2.5% (ΔT ≈ 400 K) is obtained, demonstrating significant research progress in n‐type PbTe. This work indicates that the In4SnSe4 incomplete decomposition effectively decouples the electron and phonon transports in n‐type PbTe and the strategy of utilizing the unstable additives is proven feasible. Additionally, more dynamic behaviors of additives are worth expecting and may promote more achievements for other thermoelectric systems.

Doping-induced grain refinement contributes to enhanced thermoelectric performance of n-type PbSe at room temperature

“…A key measure of this coupling strength is the ratio of m H to k L (m H / k L ). 18,58,63 The depicted room-temperature m H /k L of Cu y (-PbSe) 0.9 (GeS) 0.1 (y = 0.002-0.005) in Fig. 7a shows a signicant increase compared to that of (Pb 0.995 Sb 0.005 Se) 0.9 (GeS) 0.1 , revealing a certain degree of electron-phonon decoupling.…”

Realizing high in-plane carrier mobility in n-type SnSe crystals through deformation potential modification

“…20,21 As a commercial thermoelectric material, Bi 2 Te 3 is limited by its scarce and high-cost raw materials. 22,23 Therefore, it is imperative to seek a substitute for Bi 2 Te 3 and some alternatives have been developed in recent years, like SnSe, [24][25][26] Mg 3 Sb 2 , 27,28 PbTe, 29,30 PbSe, 31,32 etc. Among them, SnSe, with earth-abundant and nontoxic elements, has shown tremendous potential in both solid-state cooling and waste heat recovery based on its high ZT across a broad temperature range in both n-type and p-type SnSe crystals.…”

Enhancing the thermoelectric performance of SnTe-CuSbSe2with an ultra-low lattice thermal conductivity

“…7 Therefore, creating additional phonon scattering centers to restrict heat propagation through lattice vibration and reduce the κ L is highly preferable and effective toward thermoelectric optimization. In this regard, typical strategies, such as nanostructuring 8,9 and introducing crystal defects of different dimensions and scales, 10,11 are well established.…”