A Cascade Electron Source Based on Series Horizontal Tunneling Junctions

On-chip electron sources have wide potential applications in miniature vacuum electronic devices and emission efficiency is one of their performance benchmarks. A cascade source based on series metal-insulator-metal horizontal tunneling junctions proposed, where free electrons are additively extracted from each junction. with n shows a theoretical approximately {\eta}(n)=1-(1-{\eta}_0 )^n, {\eta}_0 being the single Experimentally, three Si-SiOx-Si demonstrated, achieving an as high 47.6%. This work provides new way realizing highly efficient on-chip sources.