Electron emission properties of cold cathodes based on porous silicon layer processed by electrochemical oxidation and high-pressure water vapor annealing

Porous silicon (PS) layers were processed by electrochemical oxidation (ECO) and high-pressure water vapor annealing (HWA) after they were prepared on n+-type silicon substrates with the double-cell anodic etching technique. The cathodes with a multilayer structure of Pt/PS layer/n+-Si/ohmic-contact electrode were fabricated, and their electron emission properties were investigated. The experimental results showed that it is difficult to get a sufficient and uniform oxidation for a PS layer by merely using ECO, while HWA can assist ECO to improve the oxidation quality of the PS layer, and the emission current density and efficiency of the porous silicon cathode can be increased by the combined treatment of HWA and ECO.