High-Performance Paper-Based Thermoelectric Generator from Cu₂SnS₃ Nanocubes and Bulk-Traced Bismuth

Area of Science:

• Materials Science
• Energy Harvesting
• Nanotechnology

Background:

• Flexible paper-based thermoelectric generators (PTEGs) offer advantages like low cost and eco-friendliness.
• Current PTEGs face limitations in power output due to challenges in film formation and material selection.
• Earth-abundant materials are sought to improve PTEG performance and sustainability.

Purpose of the Study:

• To synthesize and optimize copper tin sulfide (CTS) nanocubes for p-type thermoelectric applications.
• To fabricate a high-performance flexible PTEG using CTS and bismuth.
• To evaluate the device's power output, stability, and potential for waste heat energy harvesting.

Main Methods:

• Synthesis of CTS nanocubes via a hot injection method.
• Fabrication of a 20-pair flexible PTEG using CTS and bismuth legs on Kapton tape.
• Characterization of thermoelectric properties, including output power and stability through bending tests.
• Finite element simulation to support experimental findings.

Main Results:

• Achieved a high output power of 2.18 μW (0.85 nW cm^-2 K^-1) at ΔT = 80 K.
• Demonstrated device stability with <0.05% resistance change after 800 bending cycles.
• Successfully harvested ~42 nW from motorbike exhaust heat at ΔT = 20 K.

Conclusions:

• Optimized CTS nanocubes enable high-performance flexible thermoelectric generators.
• The developed PTEG exhibits excellent power output, stability, and practical energy harvesting capabilities.
• This work paves the way for efficient and sustainable thermoelectric energy solutions.