Effect of doping indium into a Bi₂Te₃ matrix on the microstructure and thermoelectric transport properties

Abstract

Indium (In) as an unconventional doping element for Bi2Te3 is applied in this work to investigate the effect of In doping on the microstructure and thermoelectric transport properties of Bi2Te3-based alloys prepared via a unique high-pressure method (high pressure and high temperature, HPHT). The synthesis time of sample is sharply shortened comparing with conventional preparation methods. Doped In into Bi2Te3 martix can induce the multiple textures and microstructures, effectively scattering different frequency phonons. In the meantime, the electrical transport properties are also significantly modulated because of In atoms as electron donors. As a result, the lattice thermal conductivity and electrical resistivity are dramatically reduced, especially a decrease of 64-54% in 305-585K for lattice thermal conductivity of the samples with In content from 1 to 2 at.%. An acceptable ZT value of 0.65 at 385K is achieved from as-prepared Bi1.9In0.1Te3 bulk materials for In as a dopant in Bi2Te3 matrix.

Changing the Band Gaps by Controlling the Distribution of Initial Particle Size to Improve the Power Factor of N‐Type Bi2Te3 Based Polycrystalline Bulks

“…Due to the strong wide‐frequency phonon scattering, a very low thermal conductivity was achieved, but the PF was just about 1.9 mW mK −2 . Guo et al doped indium into Bi 2 Te 3 to induce the multiple textures and microstructures to reduce the thermal conductivity, but the PF was just only 2.1 mW mK −2 . The reduction of grain size not only impedes phonon transport, but also blocks the carrier transport and decrease the carrier mobility .…”

Quaternary thermoelectric materials: Synthesis, microstructure and thermoelectric properties of the (Bi,Sb)2(Te,Se)3 alloys

“…In addition, our previous works indicate that high pressure and high temperature (HPHT) method for thermoelectric materials have some unique superiorities including rapid preparation, low-cost, one-step, pure phase obtained readily, performance optimization, microstructure modulation, etc. [12][13][14]. Therefore, in allusion to above difficult in quaternary (Bi,Sb) 2 (Te,Se) 3 alloys, the HPHT mothed is employed to conduct the preparation and investigation of quaternary (Bi,Sb) 2 (Te,Se) 3 alloys in this work.…”

Tuning the lattice thermal conductivity in Bismuth Telluride through Cr-doping

“…One of the best thermoelectric materials is bismuth telluride, Bi 2 T e 3 (BT) which has intrinsically low κ ph and has been studied extensively in bulk, [1,2] alloys, [3,4] thin films, nanostructures, [5] and by band engineering [6] or by chemical doping. [7][8][9] When BT is doped with In, the system behaves as electron donors and as a result it reduces both electrical resistivity and κ ph . [7] Similarly, metal and Iodide co-doping effect enhances the electrical conductivity and decreases the lattice heat conduction of BT.…”

“…[7][8][9] When BT is doped with In, the system behaves as electron donors and as a result it reduces both electrical resistivity and κ ph . [7] Similarly, metal and Iodide co-doping effect enhances the electrical conductivity and decreases the lattice heat conduction of BT. [9] Reduced κ ph is also observed in metallic Pb-doped and PbTe-precipitated BT.…”