Understanding Ultrafast and Nanoscale Electron Emission and Transport
Abstract
This AFOSR YIP award has substantially enhanced the PIs career development and built a solid foundation for the PIs future research. The research contributed to theoretical advances in: (A) Physics of diodes and ultrafast electron emission, (B) Electrical contacts and heating phenomenology, (C) Electron beam-circuit interaction, (D) Relativistic plasma physics in supercritical fields, and (E) Gas breakdown and plasma discharge. In area (A), we develop exact, analytical quantum theory for photoemission from solid surfaces and nanogaps. The exact theory considers various practical configurations, including DC bias, single frequency laser, two-color laser, two lasers of the same frequency, few-cycle laser pulses, and laser pulse train. We explore to enhance photo- and field- emission using ultrathin dielectric coatings. We analyze quantum efficiency for lasers from ultraviolet to near-infrared. We develop a generalized self-consistent model for quantum tunneling, covering Simmons law, Fowler-Nordheim law, the classical and quantum Child-Langmuir law in various limits, with their transition and current rectification. In collaboration with AFRL, we study field emission from carbon nanotube (CNT) fiber cathodes and secondary electron emission reduction of laser drilled micro-porous surfaces. We also publish a major, invited Perspective article, entitled, Space-charge limited current in nanodiodes: Ballistic, collisional, and dynamical effects. In area (B), we develop a self-consistent two-dimensional (2D) transmission line model to investigate current crowding and intense heating profiles at contacts and junctions with varying geometries and resistivities along the contact interface. It is successfully applied to ohmic, tunneling, and 2D-material-based Schottky contacts.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 13, 2022
- Accession Number
- AD1231214
Entities
People
- Peng Zhang
Organizations
- Michigan State University