Properties of carbon materials, especially fibers, for field emitter applications

An overview of different carbon materials (except carbon nanotubes (CNT)) applicable for production of field emission cathodes (FECs) is given. A classification of carbon materials is proposed, which simplifies the choice of carbon material suitable for specific field emission applications. Field emitters from carbon fibers, carbon composites and massive carbon are considered in more detail. Training techniques improving the emission current stability are described. Such training is suitable for a variety of different carbon-based cathodes.