Abstract: A quick testable subassembly with redundant isolation devices usable in a liquid crystal display has a pair of coplanar spaced apart electrode segments connected to one or more-isolation devices. Address lines are connected to the isolation devices or the electrodes. The isolation devices and electrical connections to the electrode segments can be quickly tested prior to assembly of a complete display. Redundant isolation devices are formed on the subassembly and inoperative isolation devices can be replaced by associated redundant isolation devices. A method of quickly testing the subassembly and of replacing inoperative isolation devices, and several alternate quickly testable subassembly geometries are also disclosed. A self-selecting redundant geometry and method are also disclosed.

Abstract: There is disclosed an apparatus and method for providing electrical signals representative of an image projected thereon. The apparatus includes an array of spaced apart, light sensitive elements formed from deposited semiconductor material and arranged for receiving said image. The elements are capable of effecting a detectable electrical characteristic responsive to the intensity of light received thereon from the image. The apparatus further includes isolation means for enabling the selective detection of the electrical characteristic of each element.

Abstract: A solid state semiconductor device is disclosed which is programmable so as to alter the impedance between its two terminals. In many embodiments, the device is programmable to have any one of four conditions: a first in which the electrical impedance is relatively high in both directions; a second in which the impedance is relatively high in one direction and relatively low in the opposite direction; a third in which the impedance is relatively high in the opposite direction and relatively low in the first direction; and a fourth in which the impedance is relatively low in both directions. Such a programmable device can be made with semiconductor layers which form two series coupled back-to-back diodes, each of which can be selectively programmed to lose its rectifying feature. Structures are disclosed which include a plurality of such programmable devices in one or more separately programmable planes, each with its own addressing means.

Abstract: Light influencing subassemblies and displays each having a structure in which all of the addressed pixel electronic circuitry including an optimized capacitance and including isolation devices where utilized, are located at one electrode side of each pixel electrode combination. The structure includes the subdivision of one pixel electrode into at least two spaced apart side-by-side electrode segments opposite a common electrode. The displays include light influencing material disposed between the segmented and common electrodes which form a first capacitance. A second capacitance is formed electrically in parallel with the first capacitance. The second capacitance can include an additional capacitance electrode formed separated from the segmented electrode by an insulating layer.

Abstract: A new and improved thin film field effect transistor and method provides such a transistor having increased operating frequencies and higher output currents. The transistor includes a gate electrode having a non-coplanar surface with respect to the substrate and a deposited semiconductor material overlying the gate electrode to form a current conductor channel between a source and drain. The length of the current conduction channel is determined by the thickness of the gate electrode which can be accurately controlled. As a result, short channel lengths are possible without high precision photolithography for high output currents and fast operating speeds. Further, a gate insulator is disposed between the gate and the deposited semiconductor. The gate insulator, which can be a gate oxide, can be annealed prior to the deposition of the deposited semiconductor to provide enhanced field effect mobilities. This further increases the transistor output currents and operating speeds.

Abstract: A system is disclosed which includes a transmissive liquid crystal display of the type which may display a line of characters or symbols at a time, or which may display only a raster line in combination with an energy source and a controllable and transportable medium. The medium is exposed by energy from the source of energy passing through the liquid crystal display which acts as a mask for the source of energy. The liquid crystal display may be set by electrical signals manually generated such as by a keyboard or by signals automatically generated by use of other electronic equipment. In one alternate embodiment of the invention a large area two-dimensional liquid crystal display is used as a mask. In another embodiment of the invention a liquid crystal display is used as a mask for the purpose of exposing a photoconductive drum of the type used in xerography. A reflective liquid crystal display is disclosed in yet another embodiment of the invention.

Abstract: Light influencing subassemblies and displays each having a structure in which all of the pixel electronic circuitry, including isolation devices where utilized, are located at one electrode side of each pixel electrode combination. The structure includes the subdivision of one pixel electrode into at least two spaced apart side-by-side electrode segments opposite a common electrode. The displays include light influencing material disposed between the segmented and common electrodes. The electrode segments further can include at least one isolation device coupled to at least one of the segments which facilitates selective excitation of the pixel elements and applied potential reversal across the electrodes during alternate display frames. The displays have an increased manufacturing yield, reduced capacitance and increased isolation. Also disclosed is a method of making the subassemblies and displays.

Abstract: A new and improved thin film field effect transistor has increased operating current and speed. The transistor includes a drain, an insulator, and a source formed in layers and vertically arranged with respect to a substrate and each other. The drain, however, and source layers form a plurality of non-coplanar surfaces with respect to the substrate. The device further includes a deposited semiconductor material overlying the non-coplanar surfaces to form a plurality of current conduction channels between the drain and source. A gate insulator overlies the semiconductor material, and a gate electrode overlies the gate insulator. The devices can also include carrier injection structure including a doped semiconductor material electrically coupled to the drain, the source, and the deposited semiconductor material for increasing the injection of current conduction carriers in the current conduction channels.

Abstract: A photovoltaic panel for converting light into electrical energy has enhanced energy conversion efficiency stability. The panel includes a photovoltaic device having an active region formed from a semiconductor material which exhibits an energy conversion efficiency stability directly related to the operating temperature of the device. The panel also includes means for maintaining the operating temperature of the device upon exposure to light at an elevated temperature above the ambient temperature external to the device. The active region semiconductor material is preferably an amorphous semiconductor alloy such as, for example, an amorphous silicon alloy. The operating temperature elevating means can include a thermal insulating material such as glass wool, styrofoam, or cork applied to the back side of the device to minimize heat conduction from the device.

Abstract: The continuous production of solar cells by the glow discharge (plasma) deposition of layers of varying electrical characteristics is achieved by advancing a substrate through a succession of deposition chambers. Each of the chambers is dedicated to a specific material type deposition. The chambers are mutually isolated to avoid the undesired admixture of reaction gases therebetween. Each plasma deposition is carried out in its glow discharge area, chamber, or chambers, with isolation between the plasma regions dedicated to different material types. Masking, mechanical or lithographic, can be employed relative to the substrate to cause the deposition in the desired configuration. After the semiconductor deposition is complete, top contact and anti-reflection layer or layers are deposited, followed by a protective lamination.

Abstract: A composite substrate for the fabrication of thin film electronic devices. The substrate is a multi-layer structure which includes (1) a support layer having sufficient rigidity to provide structural strength for the subsequently deposited semiconductor material and/or circuit elements, and (2) an electrically insulating layer for providing electrical isolation in both the vertical and horizontal directions. In a preferred embodiment wherein the electronic device is formed as a solar cell, the insulating layer of the composite substrate may be provided with a texturized surface to form a diffuse, light reflecting surface. Also disclosed herein is a process for fabricating the multi-layer, back reflecting composite substrate of the instant invention.

Abstract: Systems and methods for detecting and eliminating latent and existing short circuit current paths through photovoltaic devices of the type including at least one semiconductor region overlying a substrate and a layer of conductive light transmissive material overlying the at least one semiconductor region are disclosed. The latent paths are first converted to existing short circuit current paths by applying a bias voltage to the devices. The short circuit current paths which are eliminated extend through the at least one semiconductor region from the substrate to the layer of conductive light transmissive material. The resistivity of the short circuit current paths is increased substantially at the interface between the conductive light transmissive material and the semiconductor region by isolating electrically the conductive light transmissive material from the short circuit current path.

Abstract: Systems and methods for detecting and eliminating short circuit current paths through photovoltaic devices of the type including at least one semiconductor region overlying a substrate and a layer of conductive light transmissive material overlying the at least one semiconductor region are disclosed. The short circuit current paths which are eliminated extend through the at least one semiconductor region from the substrate to the layer of conductive light transmissive material. The resistivity of the short circuit current path is increased substantially at the interface between the conductive light transmissive material and the semiconductor region by isolating electrically the conductive light transmissive material from the short circuit current path.The isolation can be provided by removing the transparent conductive material from electrical contact or connection with the short circuit current path.

Abstract: The open circuit voltage and efficiency of photovoltaic devices formed from multiple regions of semiconductor alloys including at least one narrow band gap semiconductor alloy are enhanced. The device includes a pair of doped regions and an intrinsic body between the doped regions. The intrinsic body includes a first intrinsic region and an open circuit voltage enhancement means including a second intrinsic region. The second intrinsic region has a wider band gap than the band gap of the first intrinsic region and is disposed between the first intrinsic region and one of the doped regions. The open circuit enhancement means can also include a third intrinsic region also having a wider band gap than the first intrinsic region and disposed on the side of the first intrinsic region opposite the second intrinsic region.

Abstract: The recording of surface topology is obtained by first bringing the surface into contact with the imaging material-coated side of a dry process dispersion type recording film comprising a transparent substrate on which is coated a very thin, high optical density, opaque body of imaging material, preferably coated with a thin abrasion-resistant protective layer. Radiant energy is then momentarily directed to the imaging material through the transparent substrate. When the heat generated by the absorbed radiant energy is above a given threshold value at a particular location of the imaging material, the material deforms and disperses thereat to form connected or unconnected globules with spaces therebetween. Upon termination of the radiant energy, the dispersed material becomes frozen in place.

Abstract: Systems and methods for detecting and eliminating latent and existing short circuit current paths through photovoltaic devices of the type including at least one semiconductor region overlying a substrate and a layer of conductive light transmissive material overlying the at least one semiconductor region are disclosed. The latent paths are first converted to existing short circuit current paths by applying a bias voltage to the devices. The short circuit current paths which are eliminated extend through the at least one semiconductor region from the substrate to the layer of conductive light transmissive material. The resistivity of the short circuit current paths is increased substantially at the interface between the conductive light transmissive material and the semiconductor region by isolating electrically the conductive light transmissive material from the short circuit current path.

Abstract: A reduced capacitance electrode assembly for use in an alternating current plasma system provides reduced input capacitance to an associated tuning network. The assembly includes an electrode adapted to receive alternating current power for maintaining a plasma region and a plurality of electrically conductive plates. The plates are closely spaced apart by less than a predetermined distance on one side of the electrode for precluding the formation of a plasma region on the one side of the electrode and for providing a plurality of series capacitances to present a substantially reduced capacitance to the alternating current power.The reduced capacitance electrode assembly is particularly useful in a system for making photovoltaic devices wherein a plurality of amorphous semiconductor materials is deposited onto a continuous conductive substrate moving through a corresponding plurality of deposition chambers.

Abstract: Systems and methods for detecting and eliminating short circuit current paths through photovoltaic devices of the type including at least one semiconductor region overlying a substrate and a layer of conductive light transmissive material overlying the at least one semiconductor region are disclosed. The short circuit current paths which are eliminated extend through the at least one semiconductor region from the substrate to the layer of conductive light transmissive material. The resistivity of the short circuit current path is increased substantially at the interface between the conductive light transmissive material and the semiconductor region by isolating electrically the conductive light transmissive material from the short circuit current path.The isolation can be provided by removing the transparent conductive material from electrical contact or connection with the short circuit current path.

Abstract: The formation of a body of material on a substrate having at least two layers of different composition is made possible by the improved system and method of the present invention with minimized cross contamination between the respective deposition environments in which the layers are deposited. The disclosure relates more specifically to the use of the system and method for the deposition of multi-layered amorphous silicon alloys to form photovoltaic devices. As a preferred embodiment of the invention, first, second, and third glow discharge deposition chambers are provided for depositing respective first, second, and third amorphous silicon alloy layers on a substrate. The second layer is substantially intrinsic in conductivity and differs in composition from the first and third layers which are of opposite conductivity type by the absence of at least one element.

Abstract: The continuous production of solar cells by the glow discharge (plasma) deposition of layers of varying electrical characteristics is achieved by advancing a substrate through a succession of deposition chambers. Each of the chambers is dedicated to a specific material type deposition. The chambers are mutually isolated to avoid the undesired admixture of reaction gases therebetween. Each plasma deposition is carried out in its glow discharge area, chamber, or chambers, with isolation between the plasma regions dedicated to different material types. Masking, mechanical or lithographic, can be employed relative to the substrate to cause the deposition in the desired configuration. After the semiconductor deposition is complete, top contact and anti-reflection layer or layers are deposited, followed by a protective lamination.