2019/12/01 by Xincun Peng, Zhidong Wang, Peng, Xincun +15
Engineering · Physics and Astronomy · #Applied Physics (physics.app-ph) #FOS: Physical sciences #GaN-based semiconductor devices and materials #Optics (physics.optics) #Photocathodes and Microchannel Plates #solar cell performance optimization
paper · pdf · doi:10.48550/arxiv.1912.00348
openalex publication_date 2019/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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.