The attractive capability of thermoelectric (TE) materials in actualizing the conversion between temperature gradient and electrical power makes them strong candidates for waste-heat recovery as well as solid-state refrigeration [1,2,3]. The practical and widespread application of TE technology strongly relies on the development of high-performance TE materials, where the TE performance of materials is evaluated by a dimensionless figure of merit, zT = α²σT/κ. The TE parameters α and σ are the Seebeck coefficient and electrical conductivity which, respectively, constitute the power factor, PF = α²σ, used to evaluate electrical conductivity characteristics. Parameter T is the Kelvin thermodynamic temperature, while κ refers to the total thermal conductivity, which is composed of two major contributions from the charge carriers (κ_E) and the lattice (κ_L), respectively. From a computational perspective, the most ideal high-performance TE material should have a large α, high σ as well as a low κ value. What cannot be avoided is the strong coupling between thermoelectric parameters regarding carrier concentration, such as when a high σ means low α and a high κ_E, limiting the improvement of zT [4,5,6]. In order to achieve high zT in traditional or emerging TE materials, various methods and approaches have been adopted to reduce the correlation between thermal and electrical properties [7,8,9], including defect engineering, size effects, alloying effect and high-entropy engineering, etc. In addition to achieving high performance, the exploration of alternative materials consists of earth-abundant and eco-friendly components to meet the sake of clean and environmental protection is also considered as one of the most popular approaches in TE field [10,11,12,13]. In recent years, diverse bulk TE materials have been widely researched, including liquid-like Cu₂(S, Se, Te), silver-based chalcogenides, Sn(Te, S, Se), half-heuslers, etc. [14,15,16].

As an environmentally friendly and promising TE material without precious elements, the performance advantages of copper-based diamond-like TE compounds lie in their high Seebeck coefficient and low thermal conductivity [17,18,19,20,21]. Typical compounds include: Cu₃SbSe₄, with a high zT of 0.89 at 650 K [19]; Cu₂SnSe₃, with α of ~250 μV·K⁻¹ in the temperature range of 300–700 K [22]; and CuInTe₂, with a κ_L value as low as 0.3 W·m⁻¹·K⁻¹ [23], etc. Copper-based diamond-like TE compounds are a type of material that conforms to the concept of “phonon-glass electron-crystal” (PGEC) [17] materials, and their crystal structures are usually composed of two sublattices [23,24,25], in which one sublattice constitutes a conductive network, while the other acts as a thermal barrier and is sometimes also known as a charge reservoir. In 2011, Skoug et al. [24] summarized the significance of lone-pair electrons in the Cu-Sb-Se diamond-like system and demonstrated that the low intrinsic κ_L in compounds came from the interaction of lone-pair electrons with neighboring atoms. Moreover, Skoug et al. [25] also confirmed that the dominant Cu-Se network controlled the electric transport while the Sn orbitals only compensated the system for electrons. Several diamond-like crystal structures evolved from thecubic zincblende structure. Simultaneously, a series of advanced CBDL compounds have been discovered since 2009, most of which have presented outstanding TE properties. The timeline of maximum zTs and the temperature dependence of zTs for selected CBDL compounds. Taking the typical diamond-like compounds of Cu(In, Ga)Te₂, Cu₃SbSe₄, and Cu₂SnSe₃ as examples, long-term efforts have shown that they all apparently have superior TE transport properties with high zTs that exceed one. For instance, Liu et al. [23] devised a pseudocubic crystal structure in CuInTe₂ compounds; thus the highest zT of 1.24 was obtained in Ag-doped CuInTe₂ compounds. A peak zT of 1.14 was attained in a Cu₂Sn_0.90In_0.10Se₃ compound at 850 K by replacing Sn sites with In. It is also worth noting that a high average zT (zT_大道）_ave) value is desirable for 值对于整体overall TE 转换效率是理想的。例如，高conversion efficiency. For instance, a high zT_.max在 of 1 K 时为 67.873，并且.67 at 873 K, and a zT_大道的_ave of 0.73，以铜为单位实现₀, were realized in Cu0_.7银Ag_0.3加语Ga_0.4在In_0.6特Te₂ [26]周氏课题组最新研究. In the latest research of Zhou’s group [27，28]创历史新高, record-high zT_大道铜中的值分别为_ave values of 0.73 和and 0.77 were achieved in Cu₃锑硒SbSe₄-基和铜–based and Cu₃SbS₄分别基于材料，也可与其他最先进的–based materials, respectively, which were also comparable to other state-of-the-art TE化合物相媲美。因此，人们可以看到CBDL化合物有望成为TE应用的环保候选者，并实现优异的性能。 compounds. Hence one can see that CBDL compounds are expected to become environmentally friendly candidates for TE applications and to achieve excellent performances.

2. 铜基类金刚石热电化合物

Copper-based diamond-like compounds (CBDL化合物含有大量的家族成员，包括三元I-III-) compounds contain a large number of family members, which include ternary I–III–VI₂黄胆石， chalcopyrites, I₃–V–VI₄斯坦尼特，我 stannites, I₂-四至六–IV–VI₃锡，第四纪 stannites, quaternary I₂–II–IV–VI₄ compounds, and even large-二-四-六₄化合物，甚至大细胞铜₁₀cell Cu10B2C4D₁₃四面体和铜13 tetrahedrites and Cu₂₆P₂Q₆S₃₂鞘石。所选典型 colusites. The TE properties of selected typical CBDL化合物的TE特性，包括 compounds including zT_大道,_ave, zT_.max,, α²σ,, κ_L和室温下的载流子浓度（N）。, and carrier concentration (n) at room temperature 在Among CBDL化合物中，铜加特 compounds, CuGaTe₂和 and CuInTe₂是典型的 are typical Cu-III-–III–VI₂（ (III = 在，GA;In, Ga; VI = Se， S， Te） 黄铜矿结构化合物，在较高温度下表现出优异的热电性能。2012年，, S, Te) chalcopyrites structural compounds which have exhibited excellent thermoelectric properties at higher temperatures. In 2012, Plirdpring等人 et al. [29]在 achieved a record zT of 1.4 in CuGaTe中取得了创纪录的1.4 zT。₂化合物在 compound at 950 K，这表明它是TE应用领域的潜在材料。相比之下，发现, which indicated that it was a potential material in the field of TE applications. Comparatively, it was found that CuInTe是₂在 possessed a high zT of 1 K时拥有.18.850的高zT at 850 K[20]。在接下来的几年中，进行了大量研究以优化黄铜矿基材料的. A large number of studies were conducted to optimize the TE输运行为。通过缺陷工程，贝聿铭的团队在Ag掺杂CuGaTe中获得了1 transport behaviors of chalcopyrite-based materials in the following years. Through defect engineering, Pei’s team obtained a maximum K时的最大zT为 of 1.0. at 750 K in the Ag-doped CuGaTe₂化合物 compound[40]并确定空位分散是改善and identified that vacancy scattering was an active approach to improve TE运输行为的积极方法 transport behaviors[80]。张等. Zhang et al. [26]合成了一种五元合金化合物synthesized a quinary alloy compound Cu_0.7银Ag_0.3加语Ga_0.4在In_0.6特Te₂具有复杂的纳米应变域结构，具有优异的 with a complex nanosized strain domain structure, which presented excellent TE性能，在 properties with a peak zT of 1 K时峰值zT为.64.873，平均 at 873 K and an average zT为<>.<> (zT_大道）_ave) 的of 0.73。通过合成. Through compositing TiO₂纳米纤维， nanofibers. Yang等人 et al.[36]在Cachieved a maximuInTe中在m zT of 1 K时实现了.47.823的最大zT。 at 823 K in a CuInTe₂基于–based TE化合物。此外，Chen等人 compound. Moreover, Chen et al.[23]在obtained a maximum zT of 1.24 in the Cu0.75Ag0.2InTe2 compound. _0.75银_0.2英特₂复合。以上显示The above shows that Cu（(In，Ga）, Ga)Te。₂类金刚石 diamond-like TE材料具有更高的 materials have a higher zT，可与其他先进的热电材料（如s, comparable to other advanced thermoelectric materials such as PbTe[81，82，83，84]和and SnTe[85，86，87]）相媲美。此外，天然黄铜矿矿物. In addition, a natural chalcopyrite mineral, CuFeS₂ [52，53，54，55–55]，也被公认为先进的, was also recognized as an advanced CBDL热电材料。值得注意的是，铜铁矿石 thermoelectric material. It is noteworthy that the CuFeS₂化合物是 compound is a rare typical n-type TE compound among CBDL热电材料中罕见的典型n型TE化合物 thermoelectric materials[88，89]。 铜Cu₃–V–VI₄（ (V = Sb， P， As;, P, As; VI = Se、S、Te）化合物具有四方金刚石样晶体结构，可近似地视为四种等效的锌混合物的叠加，其中, S, Te) compounds with a tetragonal diamond-like crystal structure can be approximately regarded as the superposition of four equivalent zincblendes, wherein Cu₃锑硒SbSe₄被认为是有前途的 is considered as a promising TE候选者，因为它的窄带隙为 candidate owing to its narrow band gap of ~0.3 eV [19，27，47，90]。用于提高铜的. . For improving the TE性能 performance of Cu₃锑硒SbSe₄基于材料，–based materials, Li等人 et al. [45]通过结合coordinately regulated electrical and thermal transport behaviors through the incorporation of Sn掺杂和-doping and AgSb来协调调节电和热传输行为_0.98通用 电气Ge_0.02硒Se₂ inclusion, and the highest zT of 1.23 was eventually achieved at 675 K. Bo等人 et al.[1]成功地应用构型熵的概念优化了Csuccessfully applied the concept of configu的TE性能。ration entropy to optimize the TE performance of Cu₃锑硒SbSe₄，并且随着熵的增加，, and the zT比初始阶段增加了约四倍。在他们的最新报告中， increased by about four times, compared to the initial phase, with the increase of entropy. In their latest report, Zhou的小组ou’s group[27]获得了优越的平均功率因数（聚苯乙烯_大道） attained a superior average power factor (PF_ave) 的of 19 μµW·cm⁻¹·K⁻²在 in 300-723 K中，通过使用少量外来Al原子作为“稳定剂”来提供高空穴浓度，对载流子迁移率几乎没有影响。因此，结合降低的–723 K by using a small amount of foreign Al atoms as “stabilizers” to supply the high hole concentration, with almost no effect on carrier mobility. Consequently, combined with the reduced κ，创纪录的, a record-high zT为 of 1.4和 and a zT_大道的_ave of 0.72 在铜内获得were obtained within the Cu₃锑硒SbSe₄基于化合物。还介绍了一种可以协调材料–based compounds. A new unconventional doping process that can coordinate the TE性能的新型非常规掺杂工艺。除了铜 properties of materials was also presented. Apart from Cu₃锑硒SbSe₄铜, Cu₃SbS₄也是一个有前途的铜₃ is also a promising Cu3–V–VI4–type of TE材料的类型 material[28，50，51]，并且已经证明其聚苯乙烯_大道最高可达], and it has been demonstrated that its PF_ave can reach up to 16.1 μµW·cm⁻¹·K⁻²和zT_大道通过其优化，在 and the 0zTave 和 up to

0.77 Kbetween 之间高达 400.773 400 and 773 K via its optimization [28]。 不同于Different from Cu-III-–III–VI₂和铜 and Cu₃–V–VI₄化合物，三元铜 compounds, ternary Cu₂-四至六–IV–VI₃（ (IV = 锡、锇、铅;Sn, Ge, Pb; VI = Se，Te，S）化合物结晶在远离四方的更扭曲的结构中。铜, Te, S) compounds crystallize in more distorted structures that are far from tetragonal, as shown in Figure 1a. Cu₂硒SnSe₃是一种具有多种结构相的 is a kind of CBDL化合物，已被成功发现和合成，包括立方相、四方相、正交相和单斜相，涉及22种变体[62 compound with diverse structural phases, which has been found and synthesized successfully, including in cubic, tetragonal, orthogonal, and monoclinic phases involving three variants [22]。. Hu et al. [<>62] 改进了improved Cu 的 TE 传输行为the TE transport behaviors of Cu₂硒SnSe₃通过 by enhancing the crystal symmetry of it via Mg掺杂增强其晶体对称性，并通过引入位错和纳米沉淀物来增强声子散射。同样，Ming等人g-doping and intensifying the phonon scattering through the introduction of dislocations and nanoprecipitates. Similarly, Ming et al. [65]在Cuobtained a peak zT of 1 K处获得了.51.858的峰值zT。 at 858 K in the Cu₂锡Sn_0.82在In_0.18硒Se_2.7S_0.3通过调节带状结构和引入多尺度缺陷进行复合。此外，秦等人 compound through regulating the band structure and introducing multi-scale defects. In addition, a record-high zT of 1.61 was obtained at 848 K by Qin et al. [1]通过构建固有点缺陷（包括高密度堆积断层和内生长纳米针）来阻碍C. by constructing the intrinsic point defects, including high-dense stacking faults and endo-grown nanoneedles, to obstruct mid- as well as low-frequ中的中频和低频声子，从而在61 K处获得了创纪录的848.66ency phonons in zT。Cu₂硒SnSe₃化合物。除铜 compounds. Except for Cu₂硒SnSe₃铜, Cu₅一个A₂B₇（ (A = 硅、锗、锡;B = S，Se，Te），具有中心对称空间群Si, Ge, Sn; B = S, Se, Te), with a centrosymmetric space group C2/m，也是一种扭曲的, is also a kind of distorted CBDL化合物，被认为具有非中心对称立方结构，相结晶为C中心 compound which has been considered to possess a non-centrosymmetric cubic structure, with the phase crystallized as C-centered[91，92，93]。铜的不良特性An undesirable characteristic of Cu₅一个A₂B₇化合物是它们代表类似金属的行为，例如 compounds is that they represent metal-like behaviors, such as the carrier concentration and κ of Cu的载流子浓度和κ₅锡Sn₂特Te₇在 at 300 K 时是 1.39 × are 1.39×10²¹厘米 cm⁻³和 and 15.1 W·m⁻¹·K⁻¹，分别, respectively [92]。同时，锌原子已被证明是增强铜的半导体性能的有效掺杂剂. Simultaneously, zinc atoms have been proven to be effective dopants for strengthening the semiconductor properties of Cu₅锡Sn₂特Te₇化合物 compounds;Sturm等人 Sturm et al.[93]将锌掺杂剂引入铜 introduced a zinc dopant into Cu₅锡Sn₂硒Se₇和铜 and Cu₅锡Sn₂特Te₇化合物，这也支持了这一结论。特别值得注意的是，锌掺杂的效果并不理想，化合物的 compounds, which also supports this conclusion. Especially noteworthy is that the effect of zinc doping is not optimal, and the TE性能仍有待进一步提高。 performance of the compound still needs further improvement. 第四纪铜Quaternary Cu₂-二-四-六–II–IV–VI₄（ (II = 钴、锰、汞、镁、锌、镉、铁;IV = 锡，锗; Co, Mn, Hg, Mg, Zn, Cd, Fe; IV = Sn, Ge; VI = Se，S，Te）具有更复杂的四方结构的化合物也得到了广泛的研究。与三元CBDL化合物相比，季CBDL化合物的显著特征是它们具有更宽的带隙和相对较低的载流子迁移率, S, Te) compounds with more complex tetragonal structures have also been widely studied. The distinguishing features of quaternary CBDL compounds are they possess a wider bandgap and a relatively lower carrier mobility compared with the ternary CBDL compounds[68，70，76，94，95，96，97，98，99]。取斜方晶石型铜₂锰基镉₄例如Taking the orthorhombic enargite-type Cu2MnGeS4 as an example [95]，它的带隙在初始阶段为, the bandgap of it is ~1.0 eV，而在Cu中仅转换为 in the initial phase while it only converts to 0.9 eV in the Cu_2.5锰Mn_0.5GeS₄通过调整 by adjusting the ratio of Mn和 and Cu atoms. The large-cell Cu原子的比例。大细胞铜₁₀B₂C₄D₁₃  [100，101，102，103] （ (B = 银，铜;C = 钴、镍、锌、铜、锰、铁、汞、镉; Ag, Cu; C = Co, Ni, Zn, Cu, Mn, Fe, Hg, Cd; Q = Sb， Bi， As;, Bi, As; Q = Se， S）四面体具有更复杂的晶体结构。特色的, S) tetrahedrites have even more complex crystal structures. The featured“PGEC”框架也显示在 framework is also displayed in the Cu₁₂某人Sb₄S₁₃四面体，其中电传输由 tetrahedrite, where the electric transmission is controlled by a CuS控制₄网络和热传递由由 network and the thermal transmission is governed by a cavity polyhedral consisting of CuS组成的空腔多面体控制₃和 and SbS₃组 groups [100]。. In 2013年，Lu等人, Lu et al. [102]在铜中achieved an enhanced zT of 0 K时实现了.95.720的增强zT。 at 720 K in Cu₁₂某人₄Sb4S₁₃利用锌掺杂。此外， utilizing Zn-doping. Moreover, Li等人 et al. [103]在多孔Cu中在 attained a high zT of 1 K处获得了.15.723的高zT。 at 723 K in a porous Cu₁₂某人Sb₄S₁₃基于材料–based material;成功制备了基于该材料的分段单支腿装置，当Δ a segmented single-leg device based on the material was successfully fabricated which realized a high conversion efficiency of 6% when the ∆T达到6 reached up to K时，实现了419%的高转换效率。419 K. Cu₂₆P₂Q₆S₃₂  [104，105，106，107，108] （P = V， Ta， Nb， W， Mo; Q = Ge，Sn，As，Sb）镭石是其他大细胞的例子，它们在一个晶体细胞中拥有66个原子，而四面体具有colusites are other large-cell examples, which possess 66 atoms in a crystal cell while the tetrahedrites

possess 58个原子。因此，两者的共同特征是它们固有的低κ源于高结构不均匀性 atoms. Therefore, the common characteristic of both is their inherent low κ derived from high structural inhomogeneity [108，109]。例如，. For instance, Guilmeau的群’s group [105]获得了 obtained the lowest κ of 0.4 W·m的最低κ。⁻¹·K⁻¹在铜中的 at 300 K in the Cu₂₆V₂锡Sn₆S₃₂鞘钝石，归因于鞘钝石的结构复杂性和 colusite, which was attributed to the structural complexity of colusite and mass fluctuations among the Cu、V和Sn原子之间的质量波动。2018年，他们进一步阐明了与钝体固有低κ源头相关的潜在机制，以及反位点缺陷和, V and Sn atoms. In 2018, they further elucidated the potential mechanism related to the fountainhead of intrinsically low κ for a colusite along with the influence of antisite defects and S空位对载流子浓度的影响-vacancies on carrier concentration [105，106]。.