Bandgap reduction responsible for the improved thermoelectric performance of bulk polycrystalline In2–xCuxSe3 (x = 0−0.2)
Bandgap reduction responsible for the improved thermoelectric performance of bulk polycrystalline In2–xCuxSe3 (x = 0−0.2)
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DOI：
10.1063/1.3609067
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发表时间：
2011-07
影响因子：
3.2
通讯作者：
J. Cui;Xianglian Liu;Xiaojun Zhang;Yiyu Li;Yuan Deng
中科院分区：
文献类型：
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作者：
J. Cui;Xianglian Liu;Xiaojun Zhang;Yiyu Li;Yuan Deng
α-In_2Se_3是一种大禁带半导体（~ 1.4eV），其结构是由两层六角排列的硒原子组成，其中1/3的铟原子位置是空的。在这里，我们报告了带隙Eg的减少，主要是由于在主机In 2Se 3中形成Cu 2Se板，这是负责块体多晶In 2 − xCuxSe 3（x = 0.1-0.2）的热电性能的显着改善。当x = 0.2时，无量纲优值ZT和功率因数分别增加了2和3倍，在846 K，如果与无Cu的In 2Se 3相比。有趣的是，纳入Cu到晶格中的In 2Se 3的结果在形态上的变化，从amorphouslike结构所代表的In 2Se 3的可见的多晶形式归因于部分结晶的结构。这种变化在In 2Se 3的非常低的值上增强了晶格热导率κL。然而，增强是温和的，因为有效的声子散射的p…
α-In2Se3 is of large bandgap (∼1.4 eV) semiconductor and its structure is based on two-layer hexagonally packed arrays of selenium atoms with 1/3 of the sites of indium atoms being empty. Here we report a bandgap Eg reduction due mainly to the formation of a Cu2Se slab in the host In2Se3, which is responsible for the remarkable improvement of thermoelectric performance of bulk polycrystalline In2−xCuxSe3 (x = 0.1–0.2). When x = 0.2 the dimensionless figure of merit ZT and power factor were increased by a factor of 2 and 3, respectively, at 846 K if compared to those of Cu-free In2Se3. Interestingly, an incorporation of Cu into the lattice of In2Se3 results in a change in morphology from amorphouslike structure represented by In2Se3 to a visible polycrystalline form attributed to partial crystallization of the structure. This change enhances lattice thermal conductivities κL over the very low values of In2Se3. However, the enhancement is only moderate because of the effective scattering of phonons in the p...