Alvaro Sahagun

MIT Department: Electrical Engineering and Computer Science

Undergraduate Institution: University of Illinois, Chicago

Faculty Mentor: Akintunde Akinwande

Research Supervisors: Girish Rughoobur, Nedeljko Karaulac

Website: LinkedIn

2018 Research Poster


I am from Chicago Heights, Illinois and I am currently studying Electrical Engineering at the University of Illinois at Chicago. My overall educational and professional goal is to earn a Ph.D. in Nanoengineering and work in an interdisciplinary field to help develop novel devices with applications in sustainability, the environment, and medicine. My hobbies are running, weightlifting, brunch, trying new foods, playing video games, and drinking way too much coffee.

2018 Research Abstract

Characterization of Electron Emission and Field Ionization Using Gated Silicon Nanotip Arrays
Alvaro Sahagun1, Girish Rughoobur2, Nedeljko Karaulac2 and Akintunde I. Akinwande2
1Department of Electrical and Computer Engineering, University of Illinois at Chicago
2Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology

Gated silicon nanotip arrays with tip radii <10 nm have demonstrated high-output current density (~100 A/cm2), long lifetime under continuous use (>100 hours), and the ability to operate at low voltages (<30 V) due to the electric-field enhancement caused by the short distance of the tip to the gate and the sharp tip geometry. These advantages are promising for low-power, compact, and inexpensive applications such as electron emitters, X-ray sources, neutron generation, and mass spectrometry. Despite these potentials, the non-uniform radii, low breakdown voltages, and the need for an ultra-high vacuum environment have limited their use to research applications solely. In this work, we characterize the electrical properties of large arrays of nanotips (>100×100 nanotips) for both electron emission and field ionization to design devices with enhanced performance. In electron emission, we investigate the current scalability, Joule heating effects, electric-field enhancement, array utilization efficiency, and the potential for operating in poor vacuum using a graphene membrane. In addition, we study the generation of ions from argon, deuterium, and helium using the robust electric field around the nanotip, which enables a stronger ion flux at a much lower ionization voltage compared to conventional field ionizers, which are bulky, costly, and inefficient.