Field emitter arrays (FEAs) play a pivotal role in many vacuum electronic devices. In comparison to cathodes based on thermionic emission, they offer several advantages, including high-frequency switching capability, low power consumption, superior brightness and coherence, and a narrow energy distribution of the emitted electrons. These characteristics make FEAs promising candidates for high-current electron source applica-tions, such as microwave power amplifiers or mobile fast-switching X-ray sources. Literature has shown the required current densities for these applications with various FEA designs under laboratory conditions. However, the commercial success of FEA-based products is still limited as ideal ultra-high vacuum environments typically differ from actual application conditions. This thesis presents a new FEA design for high-current and high-pressure operation based on silicon nanowires (SiNWs) with an integrated extraction gate. First, the current dependent performance of ungated SiNW FEAs is compared to that of former anisotropically wet-etched pyramidal FEAs in diode configuration meas-urements. The SiNW FEAs exhibit a tenfold higher maximum current during current-voltage sweeps at similar applied electric fields. Emission currents of up to 2.5 mA can be maintained for one hour within the given extraction voltage limit of 1.4 kV at a base pressure of 10-5 mbar, even after preceding continuous operation of the sample for over 8 hours at various current levels at or above 100 µA. A study on the influence of differently doped base materials reveals potential for homogenizing the current load distribution across the array by exploiting the local current emission limiting properties of p-type silicon FEAs. The gated SiNW FEA design incorporates thermally oxidized vertical trenches between the emitting structures and the gate to minimize the risk of excessive leakage currents at high operating pressure levels. The electrical characterization of the devices in triode configuration confirms stable transmission rates of over 95% during constant current operation at 10-5 mbar, regardless of the emission current level. A maximum emission current of 630 µA is demonstrated in continuous operation for one hour without noticeable degradation at a mostly constant extraction voltage of 280 V and a pressure of 10-5 mbar. This was achieved even after 24 hours of sample operation at various current levels during preceding lifetime testing. Finally, a novel characterization method is introduced that measures the emission of individual emission sites in a spatially resolved and quantifiable manner during the integral operation of FEAs. First measurements reveal unprecedented insights into the doping dependent emission behavior of silicon FEAs. These insights can be used in future research to further optimize the lifetime of gated SiNW FEAs.     «

Field emitter arrays (FEAs) play a pivotal role in many vacuum electronic devices. In comparison to cathodes based on thermionic emission, they offer several advantages, including high-frequency switching capability, low power consumption, superior brightness and coherence, and a narrow energy distribution of the emitted electrons. These characteristics make FEAs promising candidates for high-current electron source applica-tions, such as microwave power amplifiers or mobile fast-switching X-ray...     »