Poly-C technologies for field emission electroluminescence.

摘要

Poly-crystalline diamond and carbon nanotube, with their unique mechanical, thermal, chemical and electrical properties, are attractive materials for field emission display applications. The research reported in this thesis concerns the investigation of electron emission and electro-luminescence during electron emission from diamond and carbon nanotube.; Diamond and carbon nanotube emitters were fabricated under various growth conditions using microwave plasma chemical vapor deposition system. Methane concentration in hydrogen and extrinsic doping of boron were used to vary the defect density in diamond films. Various shapes of multi-wall carbon nanotubes with diameters ranging from 20–400 nm and densities in the range of 108–109 cm−2 were grown on iron and nickel coated substrates.; The spatial mapping of electron emission over the sample surface was achieved by computer controlled x-y-z stages with 1 μm resolution in a vacuum chamber. The mapping study revealed that secondary nucleation on the diamond film surface which resulted in an increase of density of grain boundaries played an important role in improving the electron emission. Vertically aligned carbon nanotubes improved dramatically the site density and uniformity of electron emission. Carbon nanotubes were grown on a pointed metal tip with a radius of a few microns. It was demonstrated that the tube on a tip could be used as single electron source.; We have reported for the first time field emission electro-luminescence (FEEL) from poly-crystalline diamond although light emission during field emission from carbon nanotube was observed by other researchers. The analysis of spectral data indicated that the defects present in the film served as luminescent centers. The quantitative models for FEEL and hysteresis behavior of emission current were discussed. FEEL is potentially attractive for display devices without the need for phosphor-coated screens.