Thermoelectric Properties of Cu-Doped n-Type Bi2Te2.85Se0.15 Prepared by Liquid Phase Growth Using a Sliding Boat
Thermoelectric Properties of Cu-Doped n-Type Bi2Te2.85Se0.15 Prepared by Liquid Phase Growth Using a Sliding Boat
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DOI：
10.1007/s11664-014-3578-3
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发表时间：
2015-06
影响因子：
2.1
通讯作者：
H. Kitagawa;T. Matsuura;Toshihito Kato;K. Kamata
中科院分区：
文献类型：
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作者：
H. Kitagawa;T. Matsuura;Toshihito Kato;K. Kamata
采用滑移舟液相生长法（LPG）制备了N型Bi 2 Te 2. 85 Se 0. 15热电材料。选择Cu作为施主掺杂剂，研究了其对热电性能的影响。采用该工艺可获得厚度为1- 2 mm的CuxBi_2 Te_（2.85）Se_（0.15）（x=0-0.25）厚板和棒材。X射线衍射和扫描电子显微镜的结果表明，面内方向倾向于对应于六边形平面，这是热电转换的优选方向。Cu掺杂在控制导电类型和载流子（电子）浓度方面是有效的。未掺杂的Bi_2Te_2.85Se_0.15的导电类型为Wasp型，掺杂Cu后变为_（15）型。通过Cu掺杂，霍尔载流子浓度增加。在Cu0.02Bi2Te2.85Se0.15中，由于Cu掺杂量的优化和高晶体取向，实现了小的电阻率。结果表明，Cu0.02Bi2Te2.85Se0.15在310 K附近的最大功率因数约为4×10− 3 W/K2 m，具有良好的重复性。此外，通过电阻率的热循环测量，也证实了Cu0.02Bi2Te2.85Se0.15的热稳定性。因此，使用本LPG工艺制备具有大功率因数的n型Bi2Te2.85Se0.15。
N-type Bi2Te2.85Se0.15thermoelectric materials were prepared by liquid phase growth (LPG) using a sliding boat, a simple and short fabrication process for Bi2Te3-related materials. Cu was selected as a donor dopant, and its effect on thermoelectric properties was investigated. Thick sheets and bars of CuxBi2Te2.85Se0.15(x=0–0.25) of 1–2mm in thickness were obtained using the process. X-ray diffraction patterns and scanning electron micrographs showed that the in-plane direction tended to correspond to the hexagonalc-plane, which is the preferred direction for thermoelectric conversion. Cu-doping was effective in controlling conduction type and carrier (electron) concentration. The conduction type wasp-type for undoped Bi2Te2.85Se0.15and becamen-type after Cu-doping. The Hall carrier concentration was increased by Cu-doping. Small resistivity was achieved in Cu0.02Bi2Te2.85Se0.15owing to an optimized amount of Cu-doping and high crystal orientation. As a result, the maximum power factor near 310K for Cu0.02Bi2Te2.85Se0.15was approximately 4×10−3W/K2m and had good reproducibility. Furthermore, the thermal stability of Cu0.02Bi2Te2.85Se0.15was also confirmed by thermal cycling measurements of electrical resistivity. Thus,n-type Bi2Te2.85Se0.15with a large power factor was prepared using the present LPG process.