Field-emission light sources utilizing carbon nanotubes and composite phosphor made of SiO2 nanospheres covered with Y2O3:Eu

Abstract

A new concept of field-emission light sources (FELS) with electrophoretically deposited carbon nanotubes and newly discovered nanocomposite phosphor is presented. The vacuum micromachined devices were fabricated from silicon and glass wafers. Two types of miniature devices were tested. The first consisted of the silicon cathode covered with indium-tin oxide (ITO) layer and carbon nanotubes. The anode was made of glass wafer covered with ITO contact layer and nanocomposite core-shell phosphor. Nanocrystalline composite phosphor was made of silica core spheres covered with europium doped yttrium oxide Y2O3:Eu shell. For this model structure bright and uniform light emission was obtained. The second type of light source consisted of SiO2∕Y2O3:Eu phosphor deposited onto cathode, directly on carbon nanotubes layer. For this device successful but nonuniform luminescence was observed. Fabricated FELS are technologically compatible with microsystem technology and can be integrated with microfluidic systems.