| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
2025 Technical Division Student Poster Contest
|
| Presentation Title |
SPU-2: Optimizing Carbon Nanotube Field Emission Cathodes:
Height-Dependent Performance and Emission Enhancement |
| Author(s) |
Gabriel Feng, Jud Ready, Arega Margousian |
| On-Site Speaker (Planned) |
Gabriel Feng |
| Abstract Scope |
Field emission cathodes (FECs) are electron sources for devices such as Hall effect thrusters and electron microscopes. Carbon nanotubes (CNTs) are ideal FEC emitters due to their extremely high aspect ratio and correspondingly large field enhancement factor, which significantly lowers the electric field required for electron tunneling. In this work, we combine finite element simulations (COMSOL) with Fowler–Nordheim analysis of measured emission currents to investigate how CNT height influences performance in a Spindt-type CNT cathode. Simulations calibrated to experimental data identify an optimal CNT height of ~11 μm, yielding an order-of-magnitude (~10×) higher emission current at -240 V compared to conventional ~6 μm tall CNTs. However, taller CNTs approach fabrication limits (e.g., shorting risk due to gate proximity), highlighting a trade-off between maximizing emission and maintaining reliability/yield. These findings inform future fabrication of CNTFECs to optimize field emission current. |
| Proceedings Inclusion? |
Undecided |
| Keywords |
Thin Films and Interfaces, Nanotechnology, Modeling and Simulation |