Thermal-Field Emission from Cones and Wires

Field emission electron sources generally have sharp geometries in the form of cones and wires. Because they are often driven hard, their elevated current leads to elevated temperatures resulting in thermal-field emissions. A sharply curved emitter affects the emission barrier past which the electrons must be emitted, as does space charge in metal-insulator-metal (MIM) and metal-oxide-semiconductor (MOS) devices. Modeling the temperature profile of the emitter based on its resistivity gives the temperature gradient along the surface that determines total emission. Therefore, the physical capabilities, stability, and operation of the emitter depending on the material properties of the wire impacts are dependent on the temperature gradient. Specifically to model beam characteristics of hot rods and cones, modifications to the current density are based on the newly developed quadratic barrier GTF model which requires repeated evaluations along numerous differential surface elements. This model of field emission has a diverse array of applications associated with nano-devices and carbon fibers along with field emission with different material parameters.