The p-n transformation and thermoelectric property optimization of Cu1+xFeSe2 (x=0-0.05) alloys

被引：12

作者：

Zhai, Jinze ^{[1
]}

Wang, Hongchao ^{[1
]}

Su, Wenbin ^{[1
]}

Wang, Teng ^{[1
]}

Mehmood, Fahad ^{[1
]}

Wang, Xue ^{[1
]}

Chen, Tingting ^{[1
]}

Huo, Taichang ^{[1
]}

Zhang, Kaiqi ^{[1
]}

Wang, Chunlei ^{[1
]}

机构：

[1] Shandong Univ, Sch Phys, State Key Lab Crystal Mat, Jinan 250100, Shandong, Peoples R China

来源：

JOURNAL OF MATERIALS CHEMISTRY C | 2019年 / 7卷 / 31期

基金：

国家重点研发计划;

关键词：

HIGH-PERFORMANCE; POWER; NANOCRYSTALS; CONVERGENCE; BANDS;

D O I：

10.1039/c9tc01607d

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

CuFeSe2 alloys, containing earth-abundant and eco-friendly elements, are considered as environmentally friendly thermoelectric materials. In this work, the thermoelectric properties and transport were studied for nominal Cu1+xFeSe2 (x = 0.00, 0.01, 0.02, 0.03, 0.05) bulk alloys. The secondary phase of Cu2Se was detected for x > 0.01, which leads to Se competitive vacancies in the major phase. The distribution of Cu2Se was confirmed by energy-dispersive spectroscopy. Intrinsic Se vacancies were also found in all samples by X-ray fluorescence. The electrical resistivity tremendously decreased with increasing x. The Seebeck coefficients showed p-n transformation with increasing temperature for all samples. This transformation is due to the two types of Se vacancies (competitive and intrinsic), which contribute more excited electrons to the conduction band. The excess Cu significantly reduces the lattice thermal conductivity by increased phonon scatterings, including porosity, point defects, and secondary phase. The figure of merit, zT, was improved more than twice by the excess Cu. CuFeSe2 with Se vacancies is a promising n-type thermoelectric material, and its figure of merit can be optimized by excess Cu.

引用

页码：9641 / 9647

页数：7

共 41 条

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