Abstract: Provided herein is a diamond gammavoltaic cell comprising: a diamond body having a diamond body surface including first and second opposing surfaces; a low-barrier electrical contact formed on the first surface; and a high-barrier electrical contact formed on the second surface, wherein the diamond body surface that is not in contact with either the low-barrier electrical contact or the high-barrier electrical contact is at least partially surface transfer doped to provide a p-type surface.

Abstract: Provided herein is a diamond gammavoltaic cell comprising: a diamond body having a diamond body surface including first and second opposing surfaces; a low-barrier electrical contact formed on the first surface; and a high-barrier electrical contact formed on the second surface, wherein the diamond body surface that is not in contact with either the low-barrier electrical contact or the high-barrier electrical contact is at least partially surface transfer doped to provide a p-type surface.

Abstract: An electron emitter, such as for a display, has a substrate and regions of n-type material and p-type material on the substrate arranged such that there is an interface junction between the regions exposed directly to vacuum for the liberation of electrons. The p-type region may be a thin layer on top of the n-type region or the two regions may be layers on adjacent parts of the substrate with adjacent edges forming the interface junction. Alternatively, there many be multiple interface junctions formed by p-type particles or by both p-type and n-type particles. The particles may be deposited on the substrate by an ink-jet printing technique. The p-type material is preferably diamond, which may be activated to exhibit negative electron affinity.

Abstract: Parallel cathode electrodes extend across the base plate of a display. Each electrode has teeth projecting from both sides, the teeth of adjacent electrodes being closely spaced from one another by a gap that is bridged by a dot of an electron emitter material. A glass screen spaced by a vacuum gap above the base plate carries transparent anode stripes extending transversely of the cathode electrodes and a fluorescent layer of colored phosphors on the anode stripes. A voltage applied between adjacent cathode electrodes and gates conduction via each electron emitter dot. A voltage applied to an anode stripe causes a part of the current from the emitter directly below the stripe to be directed towards the anode, thereby illuminating the phosphor pixel above the emitter.

Abstract: Parallel cathode electrodes extend across the base plate of a display. Each electrode has teeth projecting from both sides, the teeth of adjacent electrodes being closely spaced from one another by a gap that is bridged by a dot of an electron emitter material. A glass screen spaced by a vacuum gap above the base plate carries transparent anode stripes extending transversely of the cathode electrodes and a fluorescent layer of coloured phosphors on the anode stripes. A voltage applied between adjacent cathode electrodes and gates conduction via each electron emitter dot. A voltage applied to an anode stripe causes a part of the current from the emitter directly below the stripe to be directed towards the anode, thereby illuminating the phosphor pixel above the emitter.

Abstract: A diamond grit surface is formed on a substrate (1) having a metal surface (2), such as nickel, by applying a paste (4) of low-grade diamond grit in a binder to the surface. After driving off the binder, the diamond coated surface is placed in a reactor chamber (10) having a microwave plasma reactor (11) and connected to a hydrogen gas pump (12). The substrate (1) is heated in the hydrogen atmosphere at a reduced pressure. The metal surface (2) acts as a catalyst in the presence of the hydrogen plasma to cause regrowth of the diamond (6), giving an improved size, shape and adhesion. The method may be used to make diamond surfaces in electron emitter devices, circuit boards or abrasive devices.

Abstract: An electron emitter (2) has a semiconductor substrate (20) doped with an n-type region (21). A diamond layer (24) is doped by ion implantation with a p-type dopant to form a graded dopant profile region (27) that increases away from the upper surface of the diamond layer (24) and a thin insulating region (28) separating the p-type region (27) from the n-type region (21). The emitter (2) has a first electrical contact (23) on a lower surface of the substrate (20) and a second electrical contact (25) on the upper surface of the diamond layer (24) such that a voltage can be applied across the emitter (2) to cause tunneling of electrons from the n-type region (21) through the insulating region (28) into the p-type region (27), causing emission of electrons from an exposed surface (29).

Abstract: A cold cathode electrode for a discharge lamp has a metal substrate supporting a layer of diamond, so as to increase the electron yield of the electrode. The substrate may be a helical nickel wire with a layer of diamond forming it into a continuous tube.

Abstract: A multi-color display has a matrix of cells containing an ionizable gas and fluorescent layers (18) that fluoresce with different colors. The display has rows of cathodes (21) and anodes (20) one of each of which is exposed within each cell so that individual cells can be energized. Each cathode (21) has at least one field-emitter (23) which may be either an uncoated cone, a cone coated with a material with a negative electron affinity, such as a diamond film (27), or formed with a negative electron affinity material, such as diamond. Cells may include an aluminum layer (17) and a dielectric layer (16) for reflecting UV and VUV radiation.