High-entropy lead chalcogenides usually exhibit high ZT values at a very narrow temperature window because the highly disordered lattice structure trades electrical conductivity for low lattice thermal conductivity (κ_lat). Here, we construct a new entropy-engineered n-type lead chalcogenide of Cu_0.004Pb_1−xSn_xSe_0.5Te_0.25S_0.25 (x = 0–0.1). Remarkably, Sn doping plainly fixes the lattice by homogenizing the charge density difference in the vicinity of Cu atoms. This facilitates Cu atoms atomically dispersing into the interstice of the matrix, removing dislocation and nanoscale precipitates that are commonly found in low-entropy lead chalcogenides. The completely dissolved Cu atoms dynamically optimized the carrier concentration over the temperature range of 300–723 K. As a result, the Cu_0.004Pb_0.99Sn_0.01Se_0.5Te_0.25S_0.25 shows a maximum power factor of ∼21 μW cm⁻¹ K⁻² at 300 K and an average power factor of ∼19 μW cm⁻¹ K⁻² from 300–723 K, rivaling the low-entropy lead compounds with ordered lattice structures. Importantly, the atomically dispersed interstitial Cu atom also markedly shortens the phonon mean free path, suppressing the minimum κ_lat to ∼0.2 W m⁻¹ K⁻¹ at 723 K which strikes the theoretical minimum. The synergistically optimized charge and thermal transport properties collectively give rise to a benchmark room temperature ZT of ∼0.6, which monotonously increases to ∼1.7 at 723 K, surpassing all the n-type entropy-engineered and low-entropy lead chalcogenides.

中文翻译：

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熵工程实现了原子分散的铜掺杂，从而使 n 型铅硫属化物具有极高的热电品质因数

高熵铅硫族化物通常在非常窄的温度窗口下表现出高ZT值，因为高度无序的晶格结构以导电率换取低晶格导热率 ( κ _lat )。在这里，我们构建了一种新的熵工程n型铅硫属化物Cu _0.004 Pb _{1− x} Sn _x Se _0.5 Te _0.25 S _0.25 ( x = 0–0.1)。值得注意的是，Sn 掺杂通过均匀化 Cu 原子附近的电荷密度差来明显地固定晶格。这有利于铜原子原子分散到基体的间隙中，消除低熵铅硫属化物中常见的位错和纳米级沉淀物。完全溶解的Cu原子在300–723 K的温度范围内动态优化载流子浓度。因此，Cu _0.004 Pb _0.99 Sn _0.01 Se _0.5 Te _0.25 S _{0.25显示出~21 μW cm} ^-1 K的最大功率因数⁻²在 300 K 时，平均功率因数为 ∼19 μW cm ⁻¹ K ⁻²在 300–723 K 范围内，可与具有有序晶格结构的低熵铅化合物相媲美。重要的是，原子分散的间隙铜原子还显着缩短了声子平均自由程，在 723 K 时将最小κ _lat抑制至~0.2 W m ^-1 K ^-1，达到了理论最小值。协同优化的电荷和热传输特性共同产生了〜0.6的基准室温ZT，在723 K时单调增加到〜1.7，超过了所有n型熵工程和低熵铅硫属化物。