Field emitters and devices

A masking layer (405) is provided on selected areas of an electrode structure that is at least partly performed, to define masked areas and unmasked areas (emitter cells 410). A first constituent with particles (408) and a second constituent (409) are then applied to the emitter cells (410), and the particles (408) are selectively directed towards the bottoms of the emitter cells (410)-e.g. by electrophoresis. The masking layer (405) is then removed from the masked areas, together with any stray quantities of the first and second constituents (408, 409) on the masking layer (405). The first and second constituents (408, 409) are then processed (e.g. by curing) to create broad area field electron emission sites in desired locations of the electrode structure.