Thermionic junction devices utilizing phonon blocking

Area of Science:

• Solid-state physics
• Materials science
• Quantum technology

Background:

• Electrothermal elements require balancing electrothermal response and phonon thermal conduction.
• Current methods face challenges in optimizing these competing conditions for energy harvesting and cooling.

Purpose of the Study:

• To propose and demonstrate solid-state thermionic junctions for efficient electrothermal operation and phonon blocking.
• To explore applications in high-efficiency refrigerators, sensors, and quantum technology cooling.

Main Methods:

• Utilized semiconductor-superconductor (Sm-S) junctions.
• Leveraged the superconducting energy gap for electrothermal response.
• Exploited acoustic transmission bottlenecks for phonon blocking.

Main Results:

• Demonstrated efficient electrothermal operation and phonon blocking in Sm-S junctions.
• Achieved a ~40% cooling of a suspended silicon chip using the junctions.
• Showcased potential for radiation detection and multistage electronic refrigeration.

Conclusions:

• Solid-state thermionic junctions offer a novel approach to phonon engineering for advanced thermal management.
• The demonstrated Sm-S junctions are promising for developing next-generation cooling devices and sensitive detectors.