Enhancing the Power Output of InSe-Based Screen-Printed Flexible Thermoelectric Generators through a Bi-Te-Co-Doping...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Flexible thermoelectric generators (FTEGs) face challenges due to material brittleness, processing complexity, and trade-offs between mechanical durability and charge transport.
• Current enhancement strategies like doping, alloying, and nanostructuring often involve complex synthesis or compromise thermoelectric performance.

Purpose of the Study:

• To investigate the effect of Bismuth/Tellurium (Bi/Te) codoping in indium selenide (InSe) for improved flexible thermoelectric generator performance.
• To develop a cost-effective and scalable fabrication method for flexible thermoelectric devices.

Main Methods:

• Synthesized Bi/Te codoped InSe powders using a conventional solid-state reaction.
• Fabricated flexible FTEGs via a screen-printing technique.
• Characterized material structure, crystallinity, and electrical properties (Seebeck coefficient, electrical conductivity, thermal conductivity) using Hall effect measurements and structural analysis.

Main Results:

• Achieved phase-pure hexagonal InSe with enhanced crystallinity at optimal Bi doping.
• Demonstrated significant improvement in electrical properties with a high Seebeck coefficient (-452 μV/K) and increased power output (∼0.14 nW at ΔT = 116 °C), a 6-fold increase compared to pristine InSe.
• Fabricated flexible devices showed exceptional mechanical reliability, maintaining performance under bending and 500 cycles with minimal resistance variation (~5%).

Conclusions:

• Bi/Te codoping in InSe offers a balanced optimization of carrier concentration and phonon scattering, leading to superior thermoelectric performance.
• The developed screen-printing method provides a scalable and industrially viable route for producing high-performance flexible thermoelectric generators.
• This work presents a promising n-type InSe-based material and device architecture for practical wearable energy-harvesting applications.