125. field enhancement in plasmonic nanostructures
Name: Shiva Piltan
Grad Year: 2017
Efficient generation of charge carriers from a metallic surface is a critical challenge in a wide variety of applications including vacuum microelectronics and photo-electrochemical devices. Replacing semiconductors with vacuum/gas as the medium of electron transport offers superior speed, power, and robustness to radiation and temperature. We propose a metallic resonant surface combining optical and electrical excitations of electrons and significantly reducing powers required using plasmon-induced enhancement of confined electric field. The properties of the device are modeled using the exact solution of the time-dependent Schrödinger equation at the barrier. Measurement results exhibit strong agreement with an analytical solution, and allow us to extract the field enhancement factor at the surface. Significant photocurrents are observed using combination of W/〖cm〗^2 optical power (compared with GW/〖cm〗^2 reported previously) and 10 volts DC excitation (compared with 100s of volts) on the surface. The model suggests optical field enhancement of 3 orders of magnitude at the metal interface due to plasmonic resonance. This simple planar structure provides valuable evidence on the electron emission mechanisms involved and it can be used for implementation of semiconductor compatible vacuum devices.
Industry Application Area(s)
Aerospace, Defense, Security | Electronics/Photonics | Energy/Clean technology