Thermoelectric Materials

Thermoelectrics (TE) are green materials that can contribute to environmental sustainability via harvesting of waste heat and converting it into electricity. IMRE has developed a complete synthesis and characterization protocol for thermoelectric materials. Material systems that have been studied include organic polymers, organic-inorganic hybrid materials, and 2D materials. A comprehensive suite of characterization tools has been developed, including tools for thermal conductivity measurements and electrical characterization at cryogenic temperatures.

Capabilities

A typical thermoelectric material should have high electrical conductivity coupled with low thermal conductivity so as to maintain a temperature gradient. IMRE has built up a series of equipment and system to help to characterize the thermoelectric properties of the new TE material, which include bulk and thin-film materials. 
  1. Thermoelectric characterization system (Bulk and thin film)
    • ZEM3-HR system (Seebeck and electrical conductivity)
    • NanoTR system (Thermal Diffusivity and Thermal Effusivity)
    • Heat capacity 
    • Thermal conductivity
          
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2. Micro-fabricated devices for temperature –dependent thermoelectric measurements of thin films

  • Developed a new and accurate technique to measure temperature dependent in-plane Seebeck coefficient and electrical conductivity of organic and inorganic thin films

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Pawan Kumar et al,Rev. Sci. Instrum. 88, 125112 (2017)

3.Liquid He closed cycle high vacuum cryostat 

  • Temperature-dependent thermoelectric measurements
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4. Physical Properties Measurement System (PPMS)

  • Offering a wide range of magnetic, thermal and electrical measurements
  • Temperature 

Range: 1.9-400 K

Sensitivity: 0.01 K

  • Magnetic field: +/- 9 T

sensitivity: 0.1 Oe

ramp rate: 1-200 Oe/sec

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(Quantum  Design)

Highlights & Achievements

IMRE has published over 20 papers and filed 5 patents in this area. Notable achievements are as follows: 

  • Modeling Charge transport in conducting polymers 

1.Promote the understanding of charge transport in conducting polymer

2.Establish the design principles for making novel organic thermoelectric

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  •  High TE performance in PEDOT:PSS polymer films 
  1. Inorganic acid post-treatment (annealing)
  2. Organic acid post-treatment (annealing)
  3. Co-solvent post-treatment (annealing)
  4. High TE performance doping materials
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  • Hybrid thermoelectrics 

1.High TE performance Hybrid TE materials

2.Perovskite with Ultra-high Seebeck coefficient

3.High TE performance hybrid organic materials

4.Full Transparent TE device

5.Flexible TE device

  • Polymer morphology dominates over energy-dependent scattering in hybrid thermoelectrics

1.Transport measurements with theoretical simulations on a prototypical PEDOT:PSS-Te(Cux) nanowire hybrid materials were performed to understand this physics of transport in this system

2.The thermoelectric performance of this hybrid is dictated by the templating effect of PEDOT resulted from Te(Cux) nanowires that enhance polymer morphology

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  • Thermoelectric performance of mixed-phase 2D materials 
    1. The thermoelectric properties of mixed-phase LixMoS2 have been studied as a function of its phase composition tuned by in situ thermally driven deintercalation
    2. It is found that the sign of Seebeck coefficient changes from positive to negative during initial reduction of the 1T/1T’ phase fraction, indicating crossover fromp- to n-type carrier conduction
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Contact

Dr. Kedar Hippalgaonkar, kedarh@imre.a-star.edu.sg

Dr. Lim Yee Fun, limyf@imre.a-star.edu.sg

General: industry@imre.a-star.edu.sg

We welcome queries and collaboration partners for both the research and commercialization of thermoelectric materials related technologies.