Transition from Fowler-Norheim Field Emission to Space Charge Limited Current Density

Summary form only given. Fowler-Nordheim law gives the current density extracted from a surface under strong fields, by treating the emission of electrons from a metal-vacuum interface in the presence of an electric field normal to the surface as a quantum mechanical tunneling process. Child´s law predicts the maximum transmitted current density by considering the space charge effect. So when the electric field becomes high enough, the emitted current density will be limited by the Child´s law. This work analyzes the transition of the transmitted current density from the Fowler-Nordheim law to the Child´s law space charge limit. The study is performed using the one-dimensional OOPD1 code. Also studied is the response of the OOPD1 emission model to strong electric fields near the transition point. Methods for increasing the current density to approach the space charge limit by modifying the device design are also described