Tailoring Thermoelectric Properties through Structure and Morphology in Chemically Synthesized n-Type Bismuth Telluride Nanostructures.

Title Tailoring Thermoelectric Properties through Structure and Morphology in Chemically Synthesized n-Type Bismuth Telluride Nanostructures.
Authors V.R. Akshay; M.V. Suneesh; M. Vasundhara
Journal Inorg Chem
DOI 10.1021/acs.inorgchem.7b00336
Abstract

Here, we report a simple, cost-effective, surfactant-assisted, and aqueous-based low-temperature reflux method for the synthesis of Bi2Te3 nanocrystals. Thermoelectric properties of n-type bismuth telluride (BT) nanostructures are reported by varying the morphology and crystal structure. Tuning the reaction time from 1 to 36 h enables the phase transformation from BiTe with a hexagonal crystal structure to Bi2Te3 with a rhombohedral crystal structure, which is evident from the refined X-ray diffraction results and high-resolution transmission electron microscopy analysis. A perfect stoichiometric balance is achieved for all the compositions, and temperature variation of the electrical resistivity of all BT nanostructures shows the typical metal to semiconducting transition near room temperature. Seebeck coefficient and Hall measurements confirm electrons as the majority carriers and show the typical characteristics of n-type BT nanostructures. The nanocrystals inherited from the optimized reaction conditions and high densification of nanoparticle interfaces contribute to the considerable reduction of thermal conductivity in BT nanostructures. Highly crystalline, uniformly distributed nanocrystals of Bi2Te3 formed for 24 h reaction time demonstrate a promising figure of merit of 0.81 at 350 K, which can be attributed to their low thermal conductivity while the high electrical conductivity is maintained. Our research could provide new possibilities in low-temperature synthesis where structural, compositional, and morphological tuning of BT nanostructures could promote practical thermoelectric applications near room temperature.

Citation V.R. Akshay; M.V. Suneesh; M. Vasundhara.Tailoring Thermoelectric Properties through Structure and Morphology in Chemically Synthesized n-Type Bismuth Telluride Nanostructures.. Inorg Chem. 2017;56(11):62646274. doi:10.1021/acs.inorgchem.7b00336

Related Elements

Bismuth

See more Bismuth products. Bismuth (atomic symbol: Bi, atomic number: 83) is a Block P, Group 15, Period 6 element with an atomic radius of 208.98040. The number of electrons in each of Bismuth's shells is 2, 8, 18, 32, 18, 5 and its electron configuration is [Xe] 4f14 5d10 6s2 6p3. Bismuth Bohr ModelThe bismuth atom has a radius of 156 pm and a Van der Waals radius of 207 pm. In its elemental form, bismuth is a silvery white brittle metal. Bismuth is the most diamagnetic of all metals and, with the exception of mercury, its thermal conductivity is lower than any other metal. Elemental BismuthBismuth has a high electrical resistance, and has the highest Hall Effect of any metal (i.e., greatest increase in electrical resistance when placed in a magnetic field). Bismuth is found in bismuthinite and bismite. It is also produced as a byproduct of lead, copper, tin, molybdenum and tungsten extraction. Bismuth was first discovered by Early Man. The name Bismuth originates from the German word 'wissmuth,' meaning white mass.

Tellurium

See more Tellurium products. Tellurium (atomic symbol: Te, atomic number: 52) is a Block P, Group 16, Period 5 element with an atomic radius of 127.60. Tellurium Bohr ModelThe number of electrons in each of tellurium's shells is 2, 8, 18, 18, 6 and its electron configuration is [Kr] 4d10 5s2 5p4. Tellurium was discovered by Franz Muller von Reichenstein in 1782 and first isolated by Martin Heinrich Klaproth in 1798. In its elemental form, tellurium has a silvery lustrous gray appearance. The tellurium atom has a radius of 140 pm and a Van der Waals radius of 206 pm. Elemental TelluriumTellurium is most commonly sourced from the anode sludges produced as a byproduct of copper refining. The name Tellurium originates from the Greek word Tellus, meaning Earth.

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