Abstract: A field electron emission material is formed by coating a substrate (221, 230) having an electrically conductive surface with a plurality of electrically conductive particles (223, 231). Each particle has a layer of electrically insulating material (222, 232) disposed either in a first location between the conductive surface of the substrate (221) and the particle (223), or in a second location between the particle (231) and the environment (237) in which the field electron emission material is disposed, but not in both of such first and second locations, so that at least some of the particles (223, 231) form electron emission sites at such first or second locations. A number of field emission devices are disclosed, utilizing such electron emission material.

Abstract: A field electron emission material has a substrate with an electrically conductive surface. Electron emission sites on the conductive surface each include a layer of electrically insulating material to define a primary interface region between the conductive surface and the insulating layer, and a secondary interface region between the insulating layer and the vacuum environment,. Each primary interface region is treated or created so as to enhance the probability of electron injection form the conductive surface into the insulating layer. Each primary interface region after such treatment or creation is either an insulator or graded from conducting adjacent the conductive surface to insulating adjacent the insulating layer.

Abstract: A field electron emission material is formed by coating a substrate (221, 230) having an electrically conductive surface with a plurality of electrically conductive particles (223, 231). Each particle has a layer of electrically insulating material (222, 232) disposed either in a first location between the disposed either in a first location between the conductive surface of the substrate (221) and the particle (223), or in a second location between the particle (231) and the environment (237) in which the field electron emission material is disposed, but not in both of such first and second locations, so that at least some of the particles (223, 231) form electron emission sites at such first or second locations. A number of field emission devices are disclosed, utilising such electron emission material.