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Long-Lifespan Turbostratic Graphene Field Emitters for High-Power Applications
Matlabjon Sattorov1,2,3, Dongpyo Hong1,2,4, Sun-Hong Min1,2
1Center for THz-Driven Biomedical Systems, Department of Physics and Astronomy, Seoul National University, Seoul08826, Republic of Korea.
ACS Applied Materials & Interfaces
|August 9, 2026
Summary
We developed a durable, freestanding turbostratic graphene film (GF) cold cathode. This edge-emitting electron source offers instant switching and sustained high current, overcoming limitations of conventional designs for high-power applications.
Area of Science:
- Materials Science
- Physics
- Nanotechnology
Background:
- Conventional cold cathodes face degradation issues under continuous thermal loads, limiting their use in high-power applications.
- Sharp-tip designs commonly used in cold cathodes are susceptible to thermal damage, hindering performance and longevity.
Purpose of the Study:
- To develop a novel cold cathode material that overcomes the thermal degradation limitations of existing technologies.
- To create a high-performance electron source suitable for demanding, high-power vacuum electron applications.
Main Methods:
- Fabrication of a freestanding, edge-emitting turbostratic graphene film (GF) via solution-phase pre-gelation of graphene oxide.
- Thermal restoration and densification of the graphene oxide to form the turbostratic structure.
- Testing the GF emission edge for direct current (DC) stability and degradation rate.
Main Results:
- The turbostratic graphene film (GF) edge demonstrated sustained DC current of 1.5 mA (52 A cm-2) for 588 hours.
- An exceptionally low degradation rate below 0.042% per hour was recorded, an order of magnitude improvement over previous carbon cathodes.
- The GF architecture effectively manages heat, bridging nanoscale field enhancement with macroscopic thermal dissipation.
Conclusions:
- The developed turbostratic graphene film (GF) cold cathode offers superior durability and performance for high-power vacuum electron devices.
- This cost-effective and scalable architecture significantly expands the application range of cold cathodes.
- The GF cathode meets critical requirements for modern high-power electron emission applications, offering a promising alternative to conventional designs.
