Amorphous Framework in Electrodeposited CuBiTe Thermoelectric Thin Films with High Room-Temperature Performance
N Padmanathan1,2, Swatchith Lal1, Devendraprakash Gautam1
1Micro-Nano Systems Centre, Tyndall National Institute, University College Cork, Dyke Parade, Lee Maltings, Cork T12 R5CP, Ireland.
ACS Applied Electronic Materials
|February 14, 2022
Summary
Copper bismuth telluride (CuBiTe) thin films show enhanced thermoelectric properties. A novel electrodeposition strategy creates a unique amorphous matrix with embedded nanocrystals, boosting performance for next-generation thermoelectric devices.
Area of Science:
- Materials Science
- Nanotechnology
- Solid State Physics
Background:
- Bismuth telluride (Bi2Te3)-based alloys are leading thermoelectric materials near room temperature.
- Enhanced thermoelectric performance is crucial for widespread adoption in generators and coolers.
Purpose of the Study:
- To develop a novel strategy for improving thermoelectric performance in bismuth telluride alloys.
- To investigate the effects of simultaneous codeposition and phase transition on CuBiTe thin films.
Main Methods:
- Electrodeposition of CuBiTe thin films with controlled Cu doping (13 atom %).
- Analysis of phase transformation from crystalline to amorphous states.
- Characterization of the alloy composition and microstructure (nanocrystalline Bi2Te3 in an amorphous matrix).
Main Results:
- Achieved a crystalline-to-amorphous phase transformation in CuBiTe alloy with 13 atom % Cu doping.
- Observed spike-shaped nanocrystalline Bi2Te3 embedded within the CuBiTe amorphous matrix.
- Demonstrated an exceptionally high power factor of 3.02 mW m⁻² K⁻², driven by an enhanced Seebeck coefficient (-275 μV K⁻¹) and high electrical conductivity (3.99 × 10⁴ S m⁻¹).
Conclusions:
- The developed codeposition and phase transition strategy effectively enhances thermoelectric properties.
- The unique nanocrystallite-embedded amorphous framework offers a promising platform for next-generation high-performance thermoelectric materials.
- The study highlights a new pathway towards advanced thermoelectric devices with superior power factors.
