CSIR Central

Tellurium-free thermoelectrics: Improved thermoelectric performance of n-type Bi2Se3 having multiscale hierarchical architecture

IR@NPL: CSIR-National Physical Laboratory, New Delhi

View Archive Info
 
 
Field Value
 
Title Tellurium-free thermoelectrics: Improved thermoelectric performance of n-type Bi2Se3 having multiscale hierarchical architecture
 
Creator Bohra, Anil K.
Bhatt, Ranu
Singh, Ajay
Basu, Ranita
Bhattacharya, Shovit
Meshram, K. N.
Ahmad, Sajid
Debnath, A. K.
Chauhan, A. K
Bhatt, Pramod
Shah, Kunjal
Bhotkar, Ketan
Sharma, Saloni
Aswal, D. K.
Muthe, K. P.
Gadkari, S. C.
 
Subject Energy Fuels
Mechanics
Thermodynamics
 
Description We report an improved thermoelectric performance of n-type Bi2Se3 bulk alloys synthesized by vacuum melt method followed by vacuum hot-pressing. In the samples so prepared, the synergetic combination of ultra low thermal conductivity (similar to 0.7 W/m K), high Seebeck coefficient (similar to-168 mu V/K), and low electrical resistivity (similar to 15 mu Omega-m) has been observed to successfully lead to a high figure-of-merit (ZT) of similar to 0.96 at 370 K. A detailed characterization of the samples reveals a presence of multiscale hierarchical defect structures i.e. atomic scale disorder arising from a multitude of factors such as large anharmonicity of Bi-Se bond due to electrostatic repulsion between the lone pair of Bi and charge of Se, nanoscale grains and dislocations trapped between mesoscale grains/grain boundaries accompanied by intrinsic layered structure of Bi2Se3. This compact layered grain structure in its consequence offers a high charge carrier mobility and thereby results into a high power factor, while multiscale hierarchical architecture accounts for the scattering of a wider spectrum of phonons leading to an ultra low thermal conductivity. In view of this promising thermoelectric performance together with the presence of copiously available constituent namely Se, the hot-pressed Bi2Se3 presents a technologically suitable and commercially viable alternative to the conventional Bi2Te3 which is based on expensive and scarcely available Te.
 
Publisher Elsevier
 
Date 2017-08-01
 
Type Article
PeerReviewed
 
Format application/pdf
 
Identifier http://npl.csircentral.net/2908/1/Tellurium-free%20thermoelectrics.pdf
Bohra, Anil K. and Bhatt, Ranu and Singh, Ajay and Basu, Ranita and Bhattacharya, Shovit and Meshram, K. N. and Ahmad, Sajid and Debnath, A. K. and Chauhan, A. K and Bhatt, Pramod and Shah, Kunjal and Bhotkar, Ketan and Sharma, Saloni and Aswal, D. K. and Muthe, K. P. and Gadkari, S. C. (2017) Tellurium-free thermoelectrics: Improved thermoelectric performance of n-type Bi2Se3 having multiscale hierarchical architecture. Energy Conversion and Management, 145. pp. 415-424. ISSN 0196-8904
 
Relation http://npl.csircentral.net/2908/