Strategic control of excess tellurium to achieve high figure-of-merit in Te-rich Bi0.5Sb1.5Te3
Abstract Increasing the Te content in stoichiometric Bi0.5Sb1.5Te3 facilitates effective control over the anti-site defects and nanostructure; however, arresting excess Te in the host matrix is challenging. Herein, we report the success of a saturation-annealing treatment in a vacuum, followed by ai...
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SpringerOpen
2025-02-01
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| Series: | Materials for Renewable and Sustainable Energy |
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| Online Access: | https://doi.org/10.1007/s40243-024-00293-4 |
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| author | Ranu Bhatt Rishikesh Kumar Pramod Bhatt Pankaj Patro Shovit Bhattacharya Mani Navaneethan Soumen Samanta Ajay Singh |
| author_facet | Ranu Bhatt Rishikesh Kumar Pramod Bhatt Pankaj Patro Shovit Bhattacharya Mani Navaneethan Soumen Samanta Ajay Singh |
| author_sort | Ranu Bhatt |
| collection | DOAJ |
| description | Abstract Increasing the Te content in stoichiometric Bi0.5Sb1.5Te3 facilitates effective control over the anti-site defects and nanostructure; however, arresting excess Te in the host matrix is challenging. Herein, we report the success of a saturation-annealing treatment in a vacuum, followed by air-quenching as a promising approach for synthesizing high figure-of-merit (zT) Bi0.5Sb1.5Te3+xTe (x = 0, 2, 5 and 10 wt%) materials. A remarkably high-power factor (α 2 σ ~ 6 mW at 300 K) is achieved in p-type Bi0.5Sb1.5Te3 + 5 wt% Te composition due to high carrier concentration (n) and good carrier mobility (µ). Microstructural analysis revealed the formation of densely interconnected polycrystalline grains featuring fine grain boundaries, planar/point defects, and strain field domains, contributing towards wide-length scale phonon scattering. The cumulative effect of drastically reduced thermal conductivity (κ ~ 0.8 W/m-K at 300 K), and enhanced power factor resulted in a record zT value ~ 2.2 at 300 K in Bi0.5Sb1.5Te3 + 5 wt% Te, with an average zT value up to 1.35 in temperatures ranging from 303 to 573 K. The COMSOL simulations predict a maximum conversion efficiency (η max ) of ~ 15%, at a temperature gradient (∆T) of 270 K, for a single-leg thermoelectric generator (TEG) developed using this material. |
| format | Article |
| id | doaj-art-b623a6e3a24d4c4aa2494e63ae57ffb9 |
| institution | Kabale University |
| issn | 2194-1459 2194-1467 |
| language | English |
| publishDate | 2025-02-01 |
| publisher | SpringerOpen |
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| series | Materials for Renewable and Sustainable Energy |
| spelling | doaj-art-b623a6e3a24d4c4aa2494e63ae57ffb92025-02-09T12:47:16ZengSpringerOpenMaterials for Renewable and Sustainable Energy2194-14592194-14672025-02-0114111410.1007/s40243-024-00293-4Strategic control of excess tellurium to achieve high figure-of-merit in Te-rich Bi0.5Sb1.5Te3Ranu Bhatt0Rishikesh Kumar1Pramod Bhatt2Pankaj Patro3Shovit Bhattacharya4Mani Navaneethan5Soumen Samanta6Ajay Singh7Technical Physics Division, Bhabha Atomic Research CentreTechnical Physics Division, Bhabha Atomic Research CentreSolid State Physics Division, Bhabha Atomic Research CentreHomi Bhabha National InstituteTechnical Physics Division, Bhabha Atomic Research CentreNanotechnology Research Centre (NRC), Faculty of Engineering and Technology, SRM Institute of Science and TechnologyTechnical Physics Division, Bhabha Atomic Research CentreTechnical Physics Division, Bhabha Atomic Research CentreAbstract Increasing the Te content in stoichiometric Bi0.5Sb1.5Te3 facilitates effective control over the anti-site defects and nanostructure; however, arresting excess Te in the host matrix is challenging. Herein, we report the success of a saturation-annealing treatment in a vacuum, followed by air-quenching as a promising approach for synthesizing high figure-of-merit (zT) Bi0.5Sb1.5Te3+xTe (x = 0, 2, 5 and 10 wt%) materials. A remarkably high-power factor (α 2 σ ~ 6 mW at 300 K) is achieved in p-type Bi0.5Sb1.5Te3 + 5 wt% Te composition due to high carrier concentration (n) and good carrier mobility (µ). Microstructural analysis revealed the formation of densely interconnected polycrystalline grains featuring fine grain boundaries, planar/point defects, and strain field domains, contributing towards wide-length scale phonon scattering. The cumulative effect of drastically reduced thermal conductivity (κ ~ 0.8 W/m-K at 300 K), and enhanced power factor resulted in a record zT value ~ 2.2 at 300 K in Bi0.5Sb1.5Te3 + 5 wt% Te, with an average zT value up to 1.35 in temperatures ranging from 303 to 573 K. The COMSOL simulations predict a maximum conversion efficiency (η max ) of ~ 15%, at a temperature gradient (∆T) of 270 K, for a single-leg thermoelectric generator (TEG) developed using this material.https://doi.org/10.1007/s40243-024-00293-4Transport propertiesMicrostructureThermoelectric generatorsCOMSOL |
| spellingShingle | Ranu Bhatt Rishikesh Kumar Pramod Bhatt Pankaj Patro Shovit Bhattacharya Mani Navaneethan Soumen Samanta Ajay Singh Strategic control of excess tellurium to achieve high figure-of-merit in Te-rich Bi0.5Sb1.5Te3 Materials for Renewable and Sustainable Energy Transport properties Microstructure Thermoelectric generators COMSOL |
| title | Strategic control of excess tellurium to achieve high figure-of-merit in Te-rich Bi0.5Sb1.5Te3 |
| title_full | Strategic control of excess tellurium to achieve high figure-of-merit in Te-rich Bi0.5Sb1.5Te3 |
| title_fullStr | Strategic control of excess tellurium to achieve high figure-of-merit in Te-rich Bi0.5Sb1.5Te3 |
| title_full_unstemmed | Strategic control of excess tellurium to achieve high figure-of-merit in Te-rich Bi0.5Sb1.5Te3 |
| title_short | Strategic control of excess tellurium to achieve high figure-of-merit in Te-rich Bi0.5Sb1.5Te3 |
| title_sort | strategic control of excess tellurium to achieve high figure of merit in te rich bi0 5sb1 5te3 |
| topic | Transport properties Microstructure Thermoelectric generators COMSOL |
| url | https://doi.org/10.1007/s40243-024-00293-4 |
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