TY - JOUR
T1 - Effects of Microstructure and Neodymium Doping on Bi2Te3Nanostructures
T2 - Implications for Thermoelectric Performance
AU - Solomon, Gil
AU - Song, Erdong
AU - Gayner, Chhatrasal
AU - Martinez, Julio A.
AU - Amouyal, Yaron
N1 - Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/5/28
Y1 - 2021/5/28
N2 - We report on an intriguing aspect of the effects of microstructure and chemistry on thermoelectric (TE) transport properties of nanostructured Bi2Te3-based compounds that are associated with their topologically insulating (TI) nature. Nanograined n-type Bi2Te3 and Bi1.94Nd0.06Te3 samples were consolidated by uniaxial hot pressing of nanoparticles (NPs) produced by solution synthesis. The grain size was controlled by changing the duration of the hot-pressing process. We found that the room-temperature values of electrical conductivity, Seebeck coefficient, and charge carrier mobility of the consolidated Bi2Te3 samples increase with the reduction of the average grain size. This phenomenon was observed earlier for Bi2Se3, which is a well-known TI material. We also found that Nd-doping reduces the electrical conductivity, Seebeck coefficient, charge carrier mobility, and thermal conductivity near room temperature (310 K). Interestingly, Nd-doping reverses the dependence of mobility on grain size compared to undoped Bi2Te3, which is associated with its magnetic moment. These observations can be utilized for further enhancement of the TE power factor of bulk nanograined TE materials to be applied for power generation near room temperature as well as cooling, in addition to the positive effect on reducing thermal conductivity due to phonon scattering.
AB - We report on an intriguing aspect of the effects of microstructure and chemistry on thermoelectric (TE) transport properties of nanostructured Bi2Te3-based compounds that are associated with their topologically insulating (TI) nature. Nanograined n-type Bi2Te3 and Bi1.94Nd0.06Te3 samples were consolidated by uniaxial hot pressing of nanoparticles (NPs) produced by solution synthesis. The grain size was controlled by changing the duration of the hot-pressing process. We found that the room-temperature values of electrical conductivity, Seebeck coefficient, and charge carrier mobility of the consolidated Bi2Te3 samples increase with the reduction of the average grain size. This phenomenon was observed earlier for Bi2Se3, which is a well-known TI material. We also found that Nd-doping reduces the electrical conductivity, Seebeck coefficient, charge carrier mobility, and thermal conductivity near room temperature (310 K). Interestingly, Nd-doping reverses the dependence of mobility on grain size compared to undoped Bi2Te3, which is associated with its magnetic moment. These observations can be utilized for further enhancement of the TE power factor of bulk nanograined TE materials to be applied for power generation near room temperature as well as cooling, in addition to the positive effect on reducing thermal conductivity due to phonon scattering.
KW - bismuth telluride
KW - electronic transport properties
KW - nanostructured chalcogenides
KW - thermal analysis
KW - thermoelectric materials
KW - topological insulators
UR - http://www.scopus.com/inward/record.url?scp=85108102445&partnerID=8YFLogxK
U2 - 10.1021/acsanm.0c03472
DO - 10.1021/acsanm.0c03472
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AN - SCOPUS:85108102445
VL - 4
SP - 4419
EP - 4431
JO - ACS Applied Nano Materials
JF - ACS Applied Nano Materials
IS - 5
ER -