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Thermoelectric Materials

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Organic hybrid thermoelectric materials

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Thermoelectric Materials

  1. 1. THERMOELECTRIC MATERIALS By Vijitha I Junior Research Fellow CSIR-NIIST
  2. 2. PIONEER IN THERMOELECTRICS Instrument used by Seebeck to observe the deflection of a compass needle (a) due to a thermoelectric induced current from heating the junction of two different metals (n and o). Thomas Seebeck
  3. 3. THERMOELECTRICITY  Temperature difference across a solid produces thermally generated emf which can drive current through a load (power generation)  Driving current through the same solid results in heating in one contact and cooling in another (refrigeration)
  4. 4. POWER GENERATION/ REFRIGERATION
  5. 5. THERMOELECTRIC EFFICIENCY Thermoelectric Figure Of Merit
  6. 6. SEEBECK COEFFICIENT Open circuit voltage produced per unit temperature difference (Thermo EMF) V  T   From transport calculations in nanoscale     B C F       E E K  n K T e B
  7. 7. THERMOELECTRIC MATERIALS The good thermoelectric materials should possess
  8. 8. DESCRIPTION OF THE PROBLEM  Electron mobility is low for organic materials  Getting ZT for n-type and p-type TE materials at same temperature α σ EC EF EV N-type α σ
  9. 9. 2 α  ZT T   INTERRELATION Figure of merit  LT e       B C F       E E K  n K T e B Wiedemann-Franz Law Seebeck coefficient
  10. 10. THE SWEET SPOT Semiconductor Semimetals & highly doped semiconductor s Metals
  11. 11. PROPOSED PLAN  Fabrication of hybrid materials  Understand underlying physics  Designing polymer composite based TE materials and refrigeration modules  Roll-to-roll printable TE circuitries  Low power rating TE refrigerators compactable with low cost organic solar cell To be competitive, ZT should be ~ 0.5
  12. 12. APPLICATIONS OF TE MATERIALS RTG Mars Science Laboratory Thermoelectric converter module Thermoelectric generator

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