Fabrication of Double-Sided Field-Emission Light Source Using Urchin-Like $\alpha \hbox {-}{\rm Fe}_{2}{\rm O}_{3}$ Microparticles

A double-sided light source based on field emission (FE) using an alternating current (ac) power source is demonstrated. Electrode plates acted as cathode or anode consisting an indium tin oxide glass, a screen-printed ZnS phosphor layer and urchin-like α-Fe₂O₃ emitters coated on the layer. Two pieces of the plates were assembled together with the coated surfaces facing each other to make a parallel-plate, diode-structure FE device with a gap distance of 300 μm. The 1- cm² device shows a double-sided luminance distribution with a turn-on field of 2.2 V/μm, 90.23% uniformity and a maximum luminance of 8750 cd/m² at 2 kV. The novel structure and ac model operation provide a double-sided luminance, high brightness, antiarcing, good thermal management, and long lifetime.