Enhancement of electron mobility and thermoelectric power factor of cobalt‐doped n ‐type Bi ₂ Te ₃

Abstract

We report the enhancement of electron mobility and power factor for 3D topological insulator Bi 2 Te 3 with Cobalt (Co) doping. Thermal variation of resistivity (ρ), thermopower (S), carrier concentration (n H ), magneto-resistance (MR), and magnetization measurements have been performed on synthesized Cobalt-doped n-type Bi 2 Te 3 , viz., Bi 2Àx Co x Te 3 (x = 0, 0.05, and 0.1) samples. Theoretical simulation of electrical and thermal transport parameters has been done in the frame of the Boltzmann equation approach and shows satisfactory agreement with experimental results. The thermoelectric performance, as estimated through power factor is found to increase with Co doping, with an enhancement of $47% is observed for Bi 1.9 Co 0.1 Te 3 sample. The positive linear MR and nearly cusp like behaviour at low field and low temperature confirms the presence of weak anti-localization (WAL) effects in pristine and Co-doped Bi 2 Te 3 samples. The field-dependent magnetization showing a cusp-like nature in the susceptibility data around zero field regions signifies the existence of topological surface state (TSS). MR along with magnetization data confirms the robustness of TSS with Co doping.

Tuning of thermoelectric performance by modulating vibrational properties in Ni-doped Sb2Te3

“…Ni inclusion significantly increases the PF to ∼2415 µWm −1 K −2 , which is more than three times higher than that of the pristine counterpart. Such high PF value was reported for Co-doped Bi 2 Te 3 samples with Co-doping [14]. However, for Sb 2 Te 3 -based system such high PF has rarely been reported, to the best of our knowledge.…”

“…Interestingly, it has been observed that most of the binary chalcogenide-based 3D TIs, e.g., Bi 2 Te 3 , and Sb 2 Te 3 attract significant attention for their exceptional thermoelectric (TE) performance [13,14]. However, unlike its TM-doped counterpart, not much work has been reported to study the TE performance of TM-doped tetradymites.…”

A Layered Bi2Te3@PPy Cathode for Aqueous Zinc‐Ion Batteries: Mechanism and Application in Printed Flexible Batteries

“…Besides, no shift of the Bi 2 Te 3 ‐related XRD peaks was discerned, proving that the PPy coating did not affect the Bi 2 Te 3 crystal structure. Similarly, Raman spectroscopy showed Bi 2 Te 3 @PPy inherits the characteristic signals of both Bi 2 Te 3 and PPy (Figure 2i and Figure S7b, Supporting Information), displaying the E u 1 , E g 2 , and A 1g 2 vibrational modes of Bi 2 Te 3, [ 29 ] and the D and G bands of carbonaceous materials. [ 30,31 ] Likewise, Fourier‐transform infrared spectroscopy results also showed the Bi 2 Te 3 @PPy to contain the fingerprints of both materials, Bi 2 Te 3 and PPy (Figure S8, Supporting Information).…”

Electrical, Thermal, and Thermoelectric Transport Properties of Co-Doped <i>n</i>-type Cu_0.008Bi₂Te_2.6Se_0.4 Polycrystalline Alloys

“…A higher zT of 1.07 at 423 K was observed in CuI-doped Bi 2 Te 2.7 Se 0.3 processed by hotdeformation [22]. Similarly, Co doping was used to enhance the electrical transport properties of pristine Bi 2 Te 3 and ptype Bi 0.5 Sb 1.5 Te 3 [23,24].…”