High thermoelectric performance of fullerene doped Bi0.5Sb1.5Te3 alloys

Abstract

In this paper, we report our recent experimental findings on the enhancement of thermoelectric performance of C 60 doped Bi 0.5 Sb 1.5 Te 3 bulk alloys. Incorporation of a small amount of C 60 significantly reduces the crystalline particle size and leads to closely packed nanostructure, whilst slightly improve the electric conductivity in the measured temperature range. In addition, a minimum thermal conductivity of 0.4 W/(mK) at 358 K was observed, which is identified to be caused by the strong lattice phonon scattering at grain boundaries, yielding a high figure-of-merit ZT = 1.47±0.07 at 358 K. Our results demonstrate that the materials can be used for the development of advanced thermoelectrics.

Significantly enhanced thermoelectric performance of Cu-doped p-type Bi0.5Sb1.5Te3 by a hydrothermal synthesis method

“…For undoped sample S1, compared with those synthesized by mechanical alloying 19 and spark plasma sintering (SPS), 39 its nanostructuring obtained by hydrothermal synthesis lowers the thermal conductivity by about 31-50% at room temperature, due to the contribution of additional phonon scattering, implying that our hydrothermal synthesis method is effective on reducing the thermal conductivity. As for sample S2, its average thermal conductivity in the temperature range of 150-350 C is about 0.71 W m À1 K À1 , approximately 12%, 21%…”

Defect engineering in thermoelectric materials: what have we learned?

“…On the other hand, because the charge carrier wavelengths are larger than the size of a fullerene molecule, scattering of electrons or holes is comparatively negligible. 356 The effect of C60 in Bi2-xSbxTe3 alloys has also been extensively studied, [357][358][359][360][361][362] with results showing that fullerene molecules act as phonon blocking sites, reducing L, and enhancing the TE performance. In addition, C60 also can efficiently reduce the L of other TE systems including skutterudites 363,364 and Cu-/Agbased chalcogenides.…”

Enhancing Thermoelectric and Mechanical Properties of p-Type (Bi, Sb)2Te3 through Rickardite Mineral (Cu2.9Te2) Incorporation

“…Up to now, many different techniques have been applied to enhance the zT values of Bi 2 Te 3 -based alloys, including doping/alloying, − defect engineering, , nanostructuring, − or texturing. − Previous studies revealed that the peak zT values of Bi 2 Te 3 -based materials outreach 1.2 around 300 K for alloyed compositions and after applying complex synthesis procedures. − Commercial materials are usually synthesized in the form of single crystals or zone-melted ingots with a high degree of texture. ,, However, the high deformation texturing techniques applied during the synthesis lead to high production cost and poor mechanical stability of the materials. ,,, …”