Diamond for use in Cold Cathode Devices, including Displays

In collaboration with colleagues in the Physics Dept, we have been studying the so called 'negative electron affinity' of diamond. This is a property which enables diamond to emit electrons from its surface without requiring large voltages. This makes possible applications such as microelectronic devices, sensors, and flat panel displays. A schematic diagram of how a diamond-based cold cathode field emitting display might be fabricated is shown below.

We are working on measuring the I-V characteristics of diamond films grown under a number of different deposition conditions, and by a variety of diverse methods, such as polycrystalline and nanocrystalline CVD diamond made by Hot Filament and Microwave reactors, diamond-like carbon (doped and undoped) made by RF plasma deposition methods, and ta-C films made by laser ablation of graphite.

	I-V curve for field emission from a Microwave Plasma-grown CVD diamond film, at an electrode distance of 30 μm. The 2 curves were taken for increasing voltage and decreasing voltage to check for hysteresis.
	Restricted Fowler-Nordheim plot from the electron emission of the MW CVD sample.