Proposal for a new self-focusing configuration involving porous silicon for field emission flat panel displays

Abstract

Process design and emission properties of gated n + polycrystalline silicon field emitter arrays for flat-panel display applicationsField emission displays ͑FEDs͒ work in principle in a similar way with conventional cathode ray tubes ͑CRTs͒, namely emitted electrons excite phosphors which in turn emit visible light. However, FEDs obtain the electrons through field emission from a distributed network of sharp emitters, and there is no special deflection system for them. The size of the light spot associated with an island of emitters ͑a pixel͒ depends on many factors, such as display geometrical dimensions and operating conditions. In this article, a special self-focusing configuration for FEDs is analyzed using a combined analytical and numerical approach. The proposed configuration involves a distributed network of electron emitting areas which are concave in shape and not plane as usual, one for each phosphor pixel. The cathode concave areas are covered with a porous silicon layer, having sharp fibrils with several nanometers radius of curvature. The concave shape has a built-in electron self-focusing feature but, as a by-product, decreases the electric field compared to the plane cathode situation. However, the field multiplication approximation applies in this case, as concerns the electric field enhancement due to both the concave cathode and fibrils. It is shown that high enough electric fields are obtained, allowing electron field emission to occur. Analytical equations are provided for the electric field on the cathode concave surface. These equations are then used in a numerical model, taking into account the electric field enhancement associated with the fibrils, their mutual influence included. This approach allows the computation of the field emitted current as function of model parameters.

Morphology and Size of Ion Induced Carbon Nanofibers: Effect of Ion Incidence Angle, Sputtering Rate, and Temperature

“…It is well known that the structures of the CNFs strongly affect the properties of devices, e.g., in field electron emission application, properly controlled number density of field electron emitters leads to the reduction in screening effect, thus resulting in a high performance of field emission devices. 24) In addition, thick emitters will be advantageous for high current emission. 25) From these standpoints, CNFs fabricated at 15 -irradiation will be promising for practical field emission devices.…”

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“…The technique described in ref. [44] may allow the fabrication of such special cathodes. The electrons emitted from CNTs at high intensity would be converged automatically.…”

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New approach to breast tumor detection based on fluorescence x-ray analysis

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