According to some aspects, a cold cathode device is provided, the device comprising a substrate, a field electron emitter disposed upon the substrate and configured to emit electrons in a first direction, and a structure encapsulating the field electron emitter, thereby creating an airtight seal around the field electron emitter, at least a portion of the structure being an atomically thin membrane positioned in the first direction with respect to the field electron emitter. According to some embodiments, at least one einzel lens may be located within the structure and configured to direct electrons emitted by the field electron emitter.