High-throughput physical vapour deposition flexible thermoelectric generators

Area of Science:

• Materials Science
• Energy Harvesting
• Nanotechnology

Background:

• Flexible thermoelectric generators (TEGs) are crucial for powering wearable technologies using body heat, but current printing methods limit material options and efficiency.
• Existing production techniques hinder the development of advanced, high-performance flexible TEGs.

Purpose of the Study:

• To investigate the compatibility of physical vapour deposition (PVD) techniques with roll-to-roll (R2R) manufacturing for flexible thermoelectric generators.
• To explore novel PVD methods for high-throughput, cost-effective production of flexible TEGs.

Main Methods:

• Sputtering of bismuth telluride (Bi2Te3) and germanium telluride (GeTe) on a flexible polyimide substrate using PVD.
• Fabrication of TEGs using R2R compatible PVD techniques, including Virtual Cathode Deposition (VCD).
• Characterization of thermoelectric properties, including Seebeck coefficient (S) and output power (P).

Main Results:

• Demonstrated a sputtered Bi2Te3/GeTe TEG on a flexible substrate with S = 140 μV/K per pair and P = 0.4 nW per pair (for a 20°C difference).
• Reported thermoelectric properties of R2R sputtered Bi2Te3 films for the first time, showing tunable power factors.
• Fabricated a Bi2Te3/Bi0.5Sb1.5Te3 TEG using VCD with S = 250 μV/K per pair and P = 0.2 nW per pair (for a 20°C difference).

Conclusions:

• PVD techniques are compatible with R2R processing for fabricating flexible TEGs.
• The developed methods enable high-speed, low-cost production of flexible TEGs with tunable thermoelectric properties.
• This work paves the way for advanced, efficient flexible thermoelectric energy harvesting solutions for wearable devices.