Fabrication of double-sided field-emission light source using a mixture of carbon nanotubes and phosphor sandwiched between two electrode layers

A double-sided surface light source based on field emission (FE) using an alternating current power source is demonstrated. Carbon-nanotube (CNT) emitters and ZnS phosphor are mixed and screen-printed onto two pieces of indium tin oxide glass that were assembled together with the coated surfaces facing each other to make a parallel-plate, diode-structure FE device. The device has a double-sided luminance distribution with a turn-on field of 2 V/μm, a good uniformity, and a stable luminance of 4000 cd/m2. The results show that CNTs not only act as good field emitters but also as an electrically conductive network around the isolated phosphors. The network prevents electric arcing and thus extends the lifetime of the device.