Displays field-emission

Field emission displays are VFDs that use field emission cathodes as the electron source. The cathodes can be molybdenum microtips,33-35 carbon films,36,37 carbon nanotubes,38" 16 diamond tips,47 or other nanoscale-emitting materials.48 Niobium silicide applied as a protective layer on silicon tip field emission arrays has been claimed to improve the emission efficiency and stability.49 ZnO Zn is used in monochrome field emission device (FED) displays but its disadvantage is that it saturates at over 200 V.29... 

Morimoto, K. Phosphors for Vacuum Fluorescent Displays and Field Emission Displays. In Phosphor Handbook. Shionoya, S. Yen, W. M. Eds. CRC Press New York, 1998, Chapter 8, pp 561-580. 

Helical (carbon) nanocoils have received attention recently255-257 for their properties as field emitter and thus for the fabrication of flat panel field emission displays. The properties depend on the electrical field generated due to the helical nanostructure, and to the characteristics of the tip of the carbon nanocoil. In fact, carbon... 

The field emission display held a particular fascination for this field, because of its potentially large market [36,44-49]. Field emission displays (FEDs) are flat panel displays, which are a flat panel equivalent of the cathode ray tube (CRT), but in which each pixel is addressed by its own electron beam from a field emitter, rather than having a beam scanned across it as in the CRT (Fig. 13.8) [44]. The emitters can be diode or triode type. The triode type is the most elegant, the diode type is lower cost. 

Fig. 13.8 Schematic of a field emission display showing triode system with carbon emitter film.

Organic light-emitting devices (OLEDs) are one of several technologies competing for the market for next-generation emissive flat panel displays. It is the one most likely to triumph over field emission displays (basically CRT technology in miniature) and plasma display panels. 

Process of chemical vapor deposition (CVD) is one of the most effective methods for preparation of flat emission cathodes. This method allows to produce different carbon structures on the cathode substrate. Depending on conditions of deposition, derivable carbon surface can be diamond-like films [1], amorphous graphite [2], various carbon constitutions, including carbon nanotubes [3], Investigation results of field emission properties produced cathodes have shown this is a promising technology for production Field Emission Display (FED). 

The role of rare earths in electroluminescent and field emission display phosphors has been of much interest and activity [134]. Flat panel displays unite all non-cathode ray tube (CRT) direct view displays. 

The cross sectional view of field emission display is shown in Fig. 12.25. 

Ravichandran D., Roy R., Chakhovskoi A. G., Hunt C. E., White W. B. and Erdei S., Fabrication of Y3AI5O12.EU thin films and powders for field emission display... 

High current densibes are also required in low-voltage field emission displays (300 V to a few kV). The phosphors must have low threshold voltage and some electrical conductivity. Efficient materials under these excitabon conditions are SrGa2S4 Ce for the blue, SrGa2S4 Eu,... 

The use of DLC in field emission displays is growing because of its properties as an electron emitter for field emission array applications. By controlling the sp /(sp + sp ) ratio the activation energy can be... 

The method is apt to produce structured nanotube films as required, for example, for field emission displays. To this purpose the catalyst is lithographed onto the substrate. The high growth rate then leads to sharply contoured structures of... 

It has been mentioned before (Section 3.4.4.3) that with an electric field applied, carbon nanotubes are able to emit electrons from their tips. This effect is termed field emission and may be employed to various appHcations. The production of field emission displays is one of the most attractive among them. These devices can be designed much brighter and more efficient in energy consumption when using carbon nanotubes. Just recently, a fuUy functional picture screen has been presented (Figure 3.107). Its production became feasible thanks to a new, ink-jet related method of generating structured nanotube patterns. Other techniques... 

Figure 3.107 Scheme of a CNT-based field emission display (a) and a complete display (b) ( Springer 2002). 

Contrary to other field emission displays that consist of arrays of tips generated by mechanical means, carbon nanotubes are stable up to much higher field intensities, while they emit already at a rather low field of <1V(xm . They can also stand high current densities of more than 1 Acm"l Both SWNTs and MWNTs are suitable for the production of field emission devices. The actual absence of defects is a more decisive parameter here. It correlates well with the efficiency of emission. MWNTs are more robust on long-term use, whereas for SWNTs, the small diameter of individual tubes is an attractive feature. 

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