Abstract: Selenium-fullerene heterojunction solar cells and techniques for fabrication thereof are provided. In one aspect, a method of forming a solar cell includes: forming a front contact on a substrate; depositing an n-type semiconducting layer on the front contact, wherein the n-type semiconducting layer comprises a fullerene or fullerene derivative; forming a p-type chalcogen absorber layer on the n-type semiconducting layer; depositing a high workfunction material onto the p-type chalcogen absorber layer, wherein the high workfunction material has a workfunction of greater than about 5.2 electron volts; and forming a back contact on the high workfunction material. Solar cells and other methods for formation thereof are also provided.

Abstract: A detector element is for detecting incident x-ray radiation. The detector element includes a scintillation layer for converting the x-ray radiation into scintillation light and a photoactive element for converting the scintillation light into an electric signal. The photoactive element includes a first photoactive absorption layer contacted by an electrode, and a second photoactive absorption layer contacted by a counter electrode. Here, the scintillation layer is arranged between the first photoactive absorption layer and the second photoactive absorption layer.

Abstract: An X-ray detector (1) includes a light detection arrangement (3) such as a CMOS photodetector, a scintillator layer (5) such as a CsI:Tl layer, a reflector layer (9) and a light emission layer (7) interposed between the scintillator layer (5) and the reflector layer (9). The light emission layer (7) may include an OLED and may have a thickness of less than 50 ?m. Thereby, a sensitivity and resolution of the X-ray detector may be improved.

Abstract: The invention relates to a photocathode having a structure that permits a decrease in the radiant sensitivity at low temperatures is suppressed so that the S/N ratio is improved. In the photocathode, a light absorbing layer is formed on the upper layer of a substrate. An electron emitting layer is formed on the upper layer of the light absorbing layer. A contact layer having a striped-shape is formed on the upper layer of the electron emitting layer. A surface electrode composed of metal is formed on the surface of the contact layer. The interval between bars in the contact layer is adjusted so as to become 0.2 ?m or more but 2 ?m or less.

Abstract: A semiconductor sensor for direct detection of electrons has a pixel structure in which a capacitance is designed to each pixel that stores a charge and converts the charge into a readable voltage. A conductive layer substantially covers the pixel structure. The conductive layer includes pixel surface coatings, each of which cover an individual pixel. Each pixel surface coating is separated from each adjoining pixel surface coating by a gap. A second conductive layer covers a surface of the gap. An insulation insulates the pixel surface coating from the second conductive layer. The conductive layers may be metal or other conductive, light impervious materials. The second conductive layer may include a capacitor electrode.

Abstract: A photocathode includes a first layer having a first energy band gap for providing absorption of light of wavelengths shorter than or equal to a first wavelength, a second layer having a second energy band gap for providing transmission of light of wavelengths longer than the first wavelength, and a third layer having a third energy band gap for providing absorption of light of wavelengths between the first wavelength and a second wavelength. The first wavelength is shorter than the second wavelength. The first, second and third layers are positioned in sequence between input and output sides of the photocathode.

Abstract: An electron beam apparatus including a hermetic container provided with an electron source, in which, when a first member is arranged in the hermetic container, at least part of the first member is coated with a film, and the film is configured in such a manner that it includes two regions, a first region and a second region different in electron density from the first region and the second region forms a network in the first region. This three-dimensional network structure allows a member being charged to be preferably controlled. Thereby, it is possible to control the effects of a member being charged which is used in an electron beam apparatus.

Abstract: A semiconductor laser CRT for driving at room temperature, whose target is pumped by an electron beam, in which a laser target is fixed to a beaker-shaped transparent glass support plate, and the glass support plate is sealed with a glass bulb using fused frit glass. Accordingly, there is no cracking of the glass bulb due to a difference in thermal expansion or destroying of a sustained airtight vacuum.

Abstract: A flat panel x-ray imager includes a gain layer (charge multiplication layer) that facilitates imaging at low x-ray exposure levels. The gain layer can be a gas chamber or a solid state material operating in an avalanche mode.

Abstract: A semiconductor cathode (11) in a semiconductor structure, in which the sturdiness of the cathode is increased by covering the emitting surface (4) with a layer of a semiconductor material (7) having a larger bandgap than the semiconductor material of the semiconductor cathode. Various measures for increasing the electron-mission efficiency are indicated.

Abstract: To prevent breakdown of an insulating layer located underneath a gate electrode, the gate electrode is connected to an external terminal via a high-ohmic resistor. The high-ohmic resistor may form part of a resistive network for biasing voltages for a plurality of gate electrodes. The resistive network may be realised partly on the insulating layer.

Abstract: Formed on a semiconductor substrate (10) is a first semiconductor layer (20; light absorbing layer) of p-type which has a first dopant concentration and generates an electron in response to light incident. Formed on the first semiconductor layer (20) is a second semiconductor layer (30; electron transfer layer) of p-type having a second dopant concentration lower than the first dopant concentration. A contact layer (50) forms a pn junction with the p-type second semiconductor layer (30). A surface electrode (80) is formed on and in ohmic contact with the contact layer (50). A third semiconductor layer (40; activation layer) is formed within an opening of the contact layer (50) on the surface of the second semiconductor layer (30). Embedded in the second semiconductor layer (30) is a semiconductor section (60; channel grid) having a third dopant concentration.

Abstract: A semiconductor cathode (11) in a semiconductor structure, in which the sturdiness of the cathode is increased by covering the emitting surface (4) with a layer of a semiconductor material (7) having a larger bandgap than the semiconductor material of the semiconductor cathode. Various measures for increasing the electron-emission efficiency are indicated.

Abstract: An x-ray image intensifier includes a photoconductive x-ray detector having an electro-optic light modulator disposed on a photoconductive detector layer. The photoconductive x-ray detector absorbs x-rays passing through an object to be imaged to form an x-ray exposure of the object. An optical image of the x-ray exposure is generated when light passes through the photoconductive x-ray detector. An imager captures optical images of the x-ray exposure. A processor coupled to the imager digitizes and stores the optical images of the x-ray exposure captured by the imager at selected intervals.

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: A field emitter is disclosed comprising a graded electron affinity surface ayer. The graded electron affinity layer provides for increased transconductance, reduced energy distribution of emitted electrons, reduced noise and increased uniformity in its operation.

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 photoelectric emission surface which is excellent in stability and reproducibility of photoelectric conversion characteristics and has a structure capable of obtaining a high photosensitivity is provided. A predetermined voltage is applied between an upper surface electrode and a lower surface electrode by a battery. Upon application of this voltage, a p-n junction formed between a contact layer and an electron emission layer is reversely biased. A depletion layer extends from the p-n junction into the photoelectric emission surface, and an electric field is formed in the electron emission layer and a light absorbing layer in a direction for accelerating photoelectrons. When incident light is absorbed in the light absorbing layer to excite photoelectrons, the photoelectrons are accelerated by the electric field toward the emission surface.

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: In order to increase the sensitivity of an image intensifier tube, the efficiency with which an electron image is formed from radiation of a first wavelength is increased. Radiation of the first wavelength is converted into radiation of a second wavelength by means of a conversion screen provided with a scintillation layer, and radiation of the second wavelength releases electrons from a photocathode which is sensitive to the second wavelength. Loss of radiation of a second wavelength, incurred because a part of this radiation does not reach the photocathode, is reduced. Radiation of the second wavelength which is not emitted in the direction of the photocathode is recaptured by providing the conversion screen with a metallic reflecting intermediate layer.

Abstract: An imaging device comprising a vacuum vessel, an electron source arranged in the vessel and a solid-state image sensor arranged to receive signal electrons emitted from the electron source. The solid-state image sensor comprises a charge transferring device, picture element electrodes, an electron multiplier layer, and a surface electrode layer. The picture element electrodes are connected to the charge transferring device and cover the major part of this device. The surface electrode layer and the electron multiplier layer are stacked on the picture element electrodes. The surface electrode layer formed on the electron multiplier layer transmits the incident signal electrons to the electron multiplier layer.

Abstract: An electron emitting device is provided for use in a flat display, an electron beam drawing apparatus, a CRT display and so on. The electron emitting device comprises a first layer having a first bandgap, a second layer formed on the first layer and having the first bandgap, a third layer formed on the second layer and having a second bandgap, which is narrower than the first bandgap, and a fourth layer formed on the third layer and having an electron emitting surface. According to this structure, a high electron emission efficiency can be obtained.

Abstract: A photoconductive device having a photoconductive layer which includes an amorphous semiconductor layer capable of charge multiplication in at least a part thereof is disclosed. The method of operating such a photoconductive device is also disclosed. By using the avalanche effect of the amorphous semiconductor layer, it is possible to realize a highly sensitive photoconductive device while maintaining low lag property. In one aspect of the present invention, the amorphous semiconductor layer is amorphous Se. In another aspect of the present invention, the amorphous semiconductor layer is composed mainly of tetrahedral elements including at least an element of hydrogen or halogens. When using the amorphous semiconductor layer composed mainly of tetrahedral elements, the charge multiplication effect is produced mainly in the interior of the amorphous semiconductor, and thus it is possible to obtain a thermally stable photoconductive device having a high sensitivity while keeping a good photoresponse.

Abstract: Tapered silicon structures, of interest for use, e.g., in atomic force microscopes, in field-emission devices, and in solid state devices are made using silicon processing technology. Resulting tapered structures have, at their tip, a radius of curvature of 10 nanometers or less. Such preferred silicon structures are particularly suited as electron emitters in display devices.

Abstract: A field emitter structure is disclosed which comprises: a substrate selec from the group consisting of a semi-insulating substrate and an insulating substrate, the substrate having first and second surfaces and at least one hole therethrough; a first conducting layer disposed on the first surface of the substrate and having at least one aperture aligned with an associated at least one hole in the substrate, the at least one aperture of the first conducting layer comprising an extraction electrode; and a second conducting layer disposed on the second surface and projecting into the at least one hole in the substrate and into the at least one associated aperture of the first conducting layer and forming at least one associated apex inside the at least one hole, the at least one associated apex comprising an associated electron field emitter.

Abstract: A wafer of neutron transmutation doped silicon having a p-n junction between extended opposite surfaces is formed with bevelled edges. A single or plurality of reverse biased signal contacts is disposed on one surface to provide a single or integrated array of avalanche photodiodes. In addition, an avalanche photodetector (APD) capable of detecting a single photoelectron or imaging multiple photoelectrons comprises a light sensitive photocathode, similar to that in a photomultiplier tube, acting as a converter to produce photoelectrons, which are then accelerated to an anode. The anode comprises a single avalanche photodiode (AP) for detecting or an array (APA) for imaging photoelectrons. The energetic photoelectrons striking the AP or the APA serve as the AP or APA's input signal, respectively.

Abstract: An improved image sensor made of photosensitive semiconductor materials with a number of pixels each including an n-type semiconductor layer, a p-type semiconductor layer and an intrinsic semiconductor layer disposed between the n-type and p-type layers. The n-type and p-type layers are made from a semiconductor material having a high resistivity. The high resistivity of the n-type layer and the p-type layer functions to prevent crosstalk currents from passing between the pixels.

Abstract: A photoconductive device having a photoconductive layer which includes an amorphous semiconductor layer capable of charge multiplication in at least a part thereof is disclosed. The method of operating such a photoconductive device is also disclosed. By using the avalanche effect of the amorphous semiconductor layer, it is possible to realize a highly sensitive photoconductive device while maintaining low lag property.

Abstract: According to the present invention, an impregnated cathode is provided wherein an alloy layer of iridium and tungsten is formed on a surface of a porous pellet impregnated with an oxide of an alkali earth metal, wherein a crystal structure of the alloy has an .epsilon.II phase comprising an hcp structure whose lattice constants a and c satisfy 2.76.ltoreq.a.ltoreq.2.78 and 4.44.ltoreq.c.ltoreq.4.46, respectively. The impregnated cathode of the present invention maintains stable electron emission characteristics from an early stage of operation.

Abstract: An image intensifier tube comprising an input screen assembly which includes a photosensitive semiconductor wafer having a substrate of one conductivity type material forming a plurality of P-N junctions with a planar array of mutually isolated islands of opposite conductivity type material, the islands protruding substantially equal distances from a common surface of the substrate, an opaque film of resistive material overlying the exposed areas of the islands and the common surface of the substrate, a layer of electroluminescent material disposed in abutting relationship with the distal ends of the islands and a layer of photoemissive material disposed in axially aligned relationship with the electroluminescent layer.

Abstract: A photoelectron beam converting device including a semiconductor substrate having a p-n junction formed between an n-type region and a p-type region and an opening portion formed on the side of the semiconductor substrate. An electron beam is generated by a light which enters from the opening portion and by a reverse voltage to be applied to the p-n junction.

Abstract: A target of an image pickup tube is formed by laminating at least a transparent conductive film, an amorphous layer consisting essentially of silicon, and an amorphous layer consisting essentially of selenium in the above order on a light-transmitting substrate.

Abstract: A photoconductive device having a photoconductive layer which includes an amorphous semiconductor layer capable of charge multiplication in at least a part thereof is disclosed. The method of operating such a photoconductive device is also disclosed. By using the avalanche effect of the amorphous semiconductor layer, it is possible to realize a highly sensitive photoconductive device while maintaining low lag property.

Abstract: An electron beam apparatus comprising a semiconductor electron emitter whose emissive surface dimensions are determined by dimensions of a p-n junction provided in the semiconductor element. By optimizing the dimensions of the emissive surface in relation to the electron-optical properties of the apparatus, an emitter is realized which combines optimum beam formation or imaging with a sufficiently large beam current and a high beam current density as required by the apparatus.

Abstract: There is disclosed an image pick-up tube target comprising an N-type conductive film formed on a transparent substrate, and a P-type photoconductive film in rectifying contact with the N-type conductive film and comprising a first layer containing As and Se, the average concentration of As in the first layer being below 8% by weight, a second layer containing As and Se, a third layer containing As and Se, the concentration of As being in the range of 8 to 20% by weight and thickness of the third layer being in the range of 5 to 50% of the total thickness of the P-type photoconductive film, in the order named, and a beam landing layer.

Abstract: By providing an intrinsic semiconductor region in a reverse biased junction cathode between an n-type surface region and a p-type zone, a maximum field is present over the intrinsic region in the operating condition. The efficiency of the cathode is increased because avalanche multiplication can now occur over a greater distance, while in addition electrons to be emitted at a sufficient energy are generated by means of tunneling.

Abstract: In a semiconductor cathode, the electron-emitting part of a pn junction is provided in the tip of a projecting portion of the semiconductor surface which is situated within an opening in an insulating layer on which an acceleration electrode is disposed. Due to the increased electric field near the tip, a reduction of the work function (Schottky effect) is obtained. As a result, cathodes can be realized in which a material reducing the work function, such as caesium, may be either dispensed with or replaced, if required, by another material, which causes lower work function, but is less volatile. The field strength remains so low that no field emission occurs and serarate cathodes can be driven individually, which is favorable for applications in electron microscopy and electron lithography.

Abstract: An optical reading device with the least cross-talk and good reading resolution, which is constructed with a plurality of metal electrodes disposed on an insulating base plate in a spaced apart relationship for each bit, a photoconductive film provided on the plurality of metal electrodes, and a transparent electrically conductive film disposed in confrontation to the plurality of metal electrodes, wherein the photoconductive film possesses high resistance value at least at the side thereof facing the metal electrode, the transparent electrically conductive film and the photoconductive film are cut out at their portions corresponding to a positional space between adjacent metal electrodes, and the photoconductive film does not substantially protrude from the transparent electrically conductive film at a portion where the transparent electrically conductive film confronts to each of the metal electrodes.

Abstract: A photocathode having a low dark current comprises a first layer consisting of P.sup.+ type semiconductor material which is transparent to all wavelengths of the light to be detected, a second layer consisting of P.sup.

Abstract: In one example of construction, a high-performance photocathode has the following structure:a transparent layer formed of P.sup.+ type semiconductor material having a forbidden band of sufficient width to ensure that this layer is transparent to the photons of the light to be detected;an absorption layer constituted by ten first sublayers formed of P.sup.

Abstract: An imaging tube particularly useful in providing a visible image corresponding to an incident infrared image in which a reflective photocathode is used to provide an electron image corresponding to the infrared image, and in which the incident image rays and the ultimate image rays move along different directions.

Abstract: An image pick-up tube target comprising an N-type conductive film formed on a transparent substrate, and P-type photoconductive film in rectifying contact with the N-type conductive film and comprising a first layer containing As, fluoride and Se, a second layer containing As, Te and Se, a portion of said second layer containing fluoride, a third layer containing As and Se, the composition of the third layer being different along the direction of thickness thereof, a fourth layer containing As and Se, wherein the concentration of As in the second layer varies continuously along the direction of thickness thereof, and in the second layer the minimum As concentration is located on the first layer side of the second layer and the maximum As concentration is located on the third layer side of the second layer.

Abstract: Deleterious effects of high capacitance in large area raster scanner image tubes, especially when employed in video cameras, can be overcome by employing the following features: (1) a plurality of transparent stripe signal electrodes; (2) a unique, multiple layer, solid state structure designed to provide a Displaced Electron Layer-Sensor-Target for imaging (hereinafter DELST), with and without; (3) photoconductive gain in the DELST structure; and (4) with and without intensifier gain in the DELST structure, the proper combination of these four features makes possible the construction of video sensor devices of extraordinarily large capacitance, having rasters generated by "low or high" velocity scanning electron beams, or a laser scanning ray. The invention provides a generic approach for the selection of features and their combination with the type of scanner best suited to any one application.

Abstract: A display tube comprising in an evacuated envelope (1) an electron gun system (6) for generating and focusing by means of a focusing lens at least two electron beams (28 to 35) on a display screen (5), which electron beams are deflected by deflection means and describe a frame on the display screen. The electron gun system (6) comprises at least two electron sources (20 to 26), the electrons in each electron beam being accelerated immediately after leaving the electron source by means of an electric field having a field strength exceeding 600 V/mm. The central axes (36) of the electron beam extend substantially parallel to each other, and all beams are converged by the focusing lens in the immediate proximity of the focus of the focusing lens, after which each separate beam is focused on the display screen by the focusing lens to form a spot.

Abstract: A photosensor including a transparent electrode for transmitting incident light and a photoconductive layer receiving light from the transparent electrode for performing photoelectric conversion, is disclosed in which the photoconductive layer is made of amorphous silicon, the amorphous silicon contains 5 to 30 atomic percent hydrogen and is doped with at least one selected from elements belonging to the groups II and III in such a manner that a region remote from the transparent electrode is higher in the concentration of the selected element than another region proximate to the transparent electrode, and a voltage is applied across the photoconductive layer so that a surface of the photoconductive layer facing the transparent electrode is at a positive potential with respect to another surface of the photoconductive layer opposite to the surface facing the transparent electrode.

Abstract: Disclosed is a photoconductive target of an image pickup tube having a transparent substrate, a transparent conductive layer formed on the transparent substrate, a photoconductive layer formed on the transparent conductive layer and containing cadmium, tellurium and selenium as major components, and a high resistance layer formed on the photoconductive layer. The film thickness of the photoconductive layer is more than 1,000 .ANG. and less than 10,000 .ANG. and the film thickness of the high resistance layer falls within the range between 2 and 10 .mu.m.

Abstract: An image pickup tube target includes a Se-As-Te photoconductive layer whose arsenic concentration changes in a direction of thickness of the Se-As-Te photoconductive layer, a carrier extraction layer having a high arsenic concentration and being contiguous to the Se-As-Te photoconductive layer, a capacitive layer having a low arsenic concentration and being contiguous to the carrier extraction layer, a doped layer obtained by doping In.sub.2 O.sub.3, MoO.sub.2 or a mixture thereof in an interface between the carrier extraction layer and the capacitive layer.

Abstract: A photoconductive image pick-up tube target comprises a transparent substrate, an N-type conductive film formed on the transparent substrate, and a P-type photoconductive film in rectifying contact with the N-type conductive film and containing Se, As and Te as sensitizer. The P-type photoconductive film includes a first layer contiguous to the N-type conductive film and containing 94.+-.1% by weight of Se and 6.+-.0.5% by weight of As, a second layer formed on the first layer and containing 64.+-.4% by weight of Se, 3.+-.0.5% by weight of As, and 33.+-.2% by weight of Te, a third layer formed on the second layer and containing Se and As, and a fluoride doped region extending over the first layer and a front half layer of the second layer and having a fluoride concentration of 0.1 to 3.0% by weight. The third layer has an As concentration which has a peak of 28.+-.1% by weight at a site contiguous to a rear half layer of the second layer and reduces gradually.

Abstract: Disclosed is a photoelectric device having at least a signal electrode, and an amorphous photoconductor layer whose principal constituent is silicon and which contains hydrogen as an indispensable constituent element, the amorphous photoconductor layer being disposed in adjacency to the signal electrode, characterized by comprising a thin layer interposed between the signal electrode and the amorphous photoconductor layer, the thin layer being made of an inorganic material whose principal constituent is at least one compound selected from the group consisting of oxides of at least one element selected from the group that consists of Si, Ti, Al, Mg, Ba, Ta, Bi, V, Ni, Th, Fe, La, Be, Sc and Co, nitrides of at least one element selected from the group that consists of Ga, Si, Mg, Te, Hf, Zr, Nb and B, and halides of at least one element selected from the group that consists of Na, Mg, Li, Ba, Ca and K.

Abstract: In a photoelectric conversion element including at least a first electrode and a photoconductive layer having an amorphous material whose indispensable constituent is silicon and which contains hydrogen as an essential constituent element on a predetermined substrate, the present invention discloses a photoelectric conversion element wherein said layer of the amorphous material is disposed on said first electrode via a light transmitting or light semi-transmitting metallic layer for adhesion with respect to said amorphous material. As said metallic layer for adhesion, preferred is a layer consisting of at least one metal selected from the group consisting of Ta, Cr, W, Nd, Mo, V and Ti. Thus, adhesion between said substrate and said amorphous material can be improved.