Effects of isovalent doping on the thermoelectric properties of environmentally-friendly phosphide Ag6Ge10P12
Effects of isovalent doping on the thermoelectric properties of environmentally-friendly phosphide Ag6Ge10P12
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DOI：
10.35848/1347-4065/ab9ef4
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发表时间：
2020-07
影响因子：
1.5
通讯作者：
H. Namiki;Y. Ota
中科院分区：
文献类型：
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作者：
H. Namiki;Y. Ota
研究了等价Cu或Sn掺杂的三元磷化物Ag_6Ge_（10）P_（12）的电输运和热输运性质。采用熔融法生长了Cu和Sn掺杂的Ag6Ge10P12多晶锭。在Ag6−xCuxGe10P12（x ≤ 0.3）和Ag6Ge10−ySnyP12（y ≤ 0.25）中，晶格热导率占总热导率的约95%。Cu和Sn掺杂的Ag6Ge10P12的晶格热导率随着掺杂浓度的增加而降低。由于晶格热导率的降低，Ag5.85Cu0.15Ge10P12的ZT优值达到10.26，比未掺杂的Ag6Ge10P12高出约60%。虽然Sn掺杂的Ag6Ge10P12的晶格热导率降低，但Sn掺杂的Ag6Ge10P12的电阻率增加，导致Sn掺杂的Ag6Ge10P12的ZT值单调减小。因此，Cu掺杂是提高Ag6Ge10P12热电性能的有效途径。
The electrical and thermal transport properties of the isovalent Cu- or Sn-doped ternary phosphide Ag6Ge10P12 have been investigated. Polycrystalline ingots of Cu- and Sn-doped Ag6Ge10P12 were grown by the melting method. In Ag6−xCuxGe10P12 (x ≤ 0.3) and Ag6Ge10−ySnyP12 (y ≤ 0.25), the lattice thermal conductivity accounted for ∼95% of the total thermal conductivity. The lattice thermal conductivity of Cu- and Sn-doped Ag6Ge10P12 decreased with increasing doping concentration. Because of the decrease of the lattice thermal conductivity, the figure of merit ZT value of Ag5.85Cu0.15Ge10P12 reached ∼0.26, which was ∼60% higher than that of non-doped Ag6Ge10P12. Although the lattice thermal conductivity of Sn-doped Ag6Ge10P12 decreased, the electrical resistivity of Sn-doped Ag6Ge10P12 increased, resulting in the ZT value of Sn-doped Ag6Ge10P12 monotonically decreasing. Therefore, Cu doping of Ag6Ge10P12 is the effective way to enhance the thermoelectric performance.