Patterned Adhesion Layer Enables Rugged Pd-MIS Hydrogen Sensors.

Area of Science:

• Materials Science
• Semiconductor Physics
• Fusion Energy Engineering

Background:

• Palladium-metal-insulator-semiconductor (Pd-MIS) sensors are crucial for detecting charge-exchange particles in fusion reactors.
• Poor adhesion between palladium (Pd) and silicon dioxide (SiO2) limits Pd thickness and sensor reliability.
• Thick Pd coatings are needed for high-energy particle resistance in tokamaks but are prone to mechanical failure.

Purpose of the Study:

• To develop a novel adhesion strategy for Pd-MIS hydrogen sensors.
• To improve the mechanical integrity of Pd coatings for fusion reactor applications.
• To enable the use of thicker Pd layers without compromising hydrogen sensing capabilities.

Main Methods:

• Fabrication of Pd-MIS devices utilizing a novel patterned adhesion layer.
• Introduction of a patterned chromium (Cr) interlayer between Pd and SiO2.
• Evaluation of adhesion properties and hydrogen uptake access.

Main Results:

• A patterned Cr interlayer significantly enhances adhesion at the Pd-SiO2 interface.
• The patterned interlayer prevents mechanical failure modes like blistering and detachment.
• Hydrogen uptake at the SiO2-Pd interface remains accessible, preserving sensor functionality.

Conclusions:

• A patterned Cr interlayer is a viable solution for improving Pd-MIS hydrogen sensor durability.
• This method allows for thicker Pd coatings, enhancing sensor robustness in harsh fusion environments.
• The developed sensors are suitable for measuring hydrogen charge-exchange neutral fluence in tokamaks.