Abstract:
Exemplary embodiments are disclosed of anti-reflective nanoporous silicon for efficient hydrogen production by photoelectrolysis of water. A nanoporous black Si is disclosed as an efficient photocathode for H2 production from water splitting half-reaction.
Abstract:
An electron gun that generate an electron flow and the application of this gun to produce rf energy or for injectors. The electron gun includes an electrostatic cavity having a first stage with emitting faces and multiple stages with emitting sections. The gun also includes a mechanism for producing an electrostatic force which encompasses the emitting faces and the multiple emitting sections so electrons are directed from the emitting faces toward the emitting sections to contact the emitting sections and generate additional electrons and to further contact other emitting sections to generate additional electrons and so on then finally to escape the end of the cavity. A method for producing a flow of electrons.
Abstract:
A photocathode device for use in an image intensifier, fabricated with a photoemissive semiconductor wafer having an active cathode layer which includes a central region of a first predetermined height surrounded by a peripheral region of a second predetermined height. The first predetermined height of the central region is configured to be greater than the second predetermined height of the peripheral region in order to create a recessed contact structure which is less likely to have unwanted emission points. A layer of conductive material covers the peripheral region to provide an electrical contact to the photocathode device. A layer of insulating material covers the layer of conductive material in order to protect the contact layer from being damage during handling operations.
Abstract:
An improved photocathode and image intensifier tube are disclosed along with a method for making both the tube and photocathode. The disclosed photocathode and image intensifier tube have an active layer comprising two or more sublayers. The first sublayer has a first concentration of a group III-V semiconductor compound while the second sublayer has a second concentration of the group III-V semiconductor compound. The multilayer active layer is coupled to a window layer.
Abstract:
The invention is directed to continuous dynodes formed by thin-film processing techniques. According to one embodiment of the invention, a continuous dynode is formed by reacting a chemical vapor in the presence of a substrate at a temperature and pressure sufficient to result in chemical vapor deposition. In another embodiment, the layer is formed by liquid phase deposition and in another embodiment, the layer is formed by nitriding or oxidizing a substrate.
Abstract:
The present invention provides a photoemission device excellent in quantum efficiency of photoelectric conversion, a high-sensitive electron tube employing it, and a high-sensitive photodetecting apparatus. A photoemission device of the present invention is arranged to have a photon absorbing layer for absorbing incident photons to excite photoelectrons, an insulator layer layered on one surface of the photon absorbing layer, a lead electrode layered on the insulator layer, and a contact formed on the other surface of the photon absorbing layer to apply a predetermined polarity voltage between the lead electrode and the other surface of the photon absorbing layer, whereby the photoelectrons excited by the incident photons entering the photon absorbing layer and moving toward the one side are made to be emitted by an electric field formed between the lead electrode and the one surface by the predetermined polarity voltage.
Abstract:
A process of producing a highly spin-polarized electron beam, including the steps of applying a light energy to a semiconductor device comprising a first compound semiconductor layer having a first lattice constant and a second compound semiconductor layer having a second lattice constant different from the first lattice constant, the second semiconductor layer being in junction contact with the first semiconductor layer to provide a strained semiconductor heterostructure, a magnitude of mismatch between the first and second lattice constants defining an energy splitting between a heavy hole band and a light hole band in the second semiconductor layer, such that the energy splitting is greater than a thermal noise energy in the second semiconductor layer in use; and extracting the highly spin-polarized electron beam from the second semiconductor layer upon receiving the light energy. A semiconductor device for emitting, upon receiving a light energy, a highly spin-polarized electron beam, including a first compound semiconductor layer formed of gallium arsenide phosphide, GaAs.sub.1-x P.sub.x, and having a first lattice constant; and a second compound semiconductor layer provided on the first semiconductor layer, the second semiconductor layer having a second lattice constant different from the first lattice constant and a thickness, t, smaller than the thickness of the first semiconductor layer.
Abstract:
A single-crystal, multi-layer device incorporating an IR absorbing layer that is compositionally different from the Ga.sub.x Al.sub.1-x Sb layer which acts as the electron emitter. Many different IR absorbing layers can be envisioned for use in this embodiment, limited only by the ability to grow quality material on a chosen substrate. A non-exclusive list of possible IR absorbing layers would include GaSb, InAs and InAs/Ga.sub.w In.sub.y Al.sub.1-y-w Sb superlattices. The absorption of the IR photon excites an electron into the conduction band of the IR absorber. An externally applied electric field then transports electrons from the conduction band of the absorber into the conduction band of the Ga.sub.x Al.sub.1-x Sb, from which they are ejected into vacuum. Because the band alignments of Ga.sub.x Al.sub.1-x Sb can be made the same as that of GaAs, emitting efficiencies comparable to GaAs photocathodes are obtainable. The present invention provides a photocathode that is responsive to wavelengths within the range of 0.9 .mu.m to at least 10 .mu.m.
Abstract:
An electron emitting device, comprising: a first electrode provided on a substrate; a first layer provided on said electrode and capable of undergoing transition from an electrically high resistance state to a low resistance state when irradiated by a radiant ray; and a conductive layer, an insulating layer and a second electrode, laminated on said first layer. An electron generator includes the electron emitting device as well as an applicator for applying an electric field to said device, and an irradiator for irradiating a radiant ray on the device. A method for driving the electron emitting device is also provided.