Thermoelectric Sensor with CuI Supported on Rough Glass.

Area of Science:

• Materials Science
• Nanotechnology
• Energy Harvesting

Background:

• Thermoelectric generators (TEGs) convert heat to electricity, enabling thermal energy harvesting and self-powered sensors.
• Copper iodide (CuI) is a promising p-type thermoelectric material, but its application is limited by poor adhesion on glass substrates.
• Existing fabrication methods for CuI films on glass suffer from stress-induced delamination, hindering microfabrication.

Purpose of the Study:

• To develop a novel substrate for improved CuI film adhesion and enhanced thermoelectric performance.
• To investigate the effect of substrate surface morphology on the growth and properties of CuI thermoelectric layers.
• To demonstrate a microfabricated thermoelectric sensor with improved sensitivity and stability.

Main Methods:

• Fabrication of a rough soda-lime glass substrate with nanoscale cavities using reactive ion etching.
• Preparation of CuI thermoelectric layers on both rough and bare glass substrates via vapor iodination.
• Characterization of the CuI/In-CoSb3 thermoelectric sensor's performance, including open-circuit voltage measurements.
• Analysis of the substrate's influence on CuI layer adhesion, crystallinity, and composition.

Main Results:

• The rough glass substrate with nanocavities significantly improved CuI layer adhesion compared to bare glass.
• Thermoelectric sensors fabricated on rough glass exhibited a substantially higher open-circuit voltage (13.7 mV/K) versus bare glass (0.9 mV/K).
• The nanocavities provided mechanical interlocking and influenced CuI crystallinity and composition, leading to enhanced thermopower.

Conclusions:

• A roughened glass substrate with nanoscale cavities is an effective approach to enhance the adhesion and thermoelectric performance of CuI films.
• This substrate modification overcomes limitations of previous methods, enabling microfabrication of sensitive and stable thermoelectric sensors.
• The findings pave the way for advanced thermal energy harvesting and temperature sensing applications.