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Thermoelectric Materials


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Organic hybrid thermoelectric materials

Published in: Science
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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)
  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