Field emission device with back gated structure

Analysis and performance optimization of a back-gated field emission device is provided. The device consists of an anode, electron emitting cathodes and gate electrode that are placed below the cathode (“back gate”). The role of a back gate is to control electron emission from the cathode by changing the voltage on the back gate. The top of the cathode is selectively coated with an electron emissive material/structure that presents better emission properties when compared to the material of the cathode. The role of the cathode geometry, back gate voltage, cathode-gate distance, distance between cathode electrodes, the back gate dielectric, as well as field emission characteristics of the emitting material on the top of a cathode were analyzed using continuum electrostatic simulations. The proposed design significantly facilitates fabrication of the field emitting devices while decreasing the amount of charge lost to the gate and potentially reducing the likelihood of catastrophic discharges.