Quantum Efficiency Enhancement by Mie Resonance from GaAs Photocathodes Structured with Surface Nanopillar Arrays
Abstract
A new type of negative electron affinity (NEA) photocathode based on GaAs nanopillar array (NPA) Mie-type resonators was demonstrated for the first time. For visible wavelengths, the Mie resonances in GaAs NPA reduced light reflectivity to less than 6 percent compared to a typical value great then 35 percent. Other benefits of NPA resonators include an enhanced density of optical states due to increased light concentration and increased electron emission area. These features resulted in improved photoemission performance at the resonance wavelength demonstrating maximum quantum efficiency 3.5 times greater than a GaAs wafer photocathode without the NPA structure. This optically dark photocathode (sub-percentage light reflectance over visible wavelengths) but possessing electrically high-brightness (enhanced electron emission) provides new opportunities for practical applications such as large-scale electron accelerators, high-resolution night-vision imaging and low energy electron microscopy.
Keywords
Cite
@article{arxiv.1912.00348,
title = {Quantum Efficiency Enhancement by Mie Resonance from GaAs Photocathodes Structured with Surface Nanopillar Arrays},
author = {Xincun Peng and Zhidong Wang and Yun Liu and Dennis M. Manos and Matt Poelker and Marcy Stutzman and Bin Tang and Shukui Zhang and Jijun Zou},
journal= {arXiv preprint arXiv:1912.00348},
year = {2019}
}