Abstract: An improved large area photovoltaic device includes a plurality of electrically interconnected smaller area cells. The smaller area cells each have a laterally disposed bus bar and are disposed in overlapping relationships so that the bus bar of a given cell is beneath the substrate of the adjacent overlapping cell. In this manner the surface of the resulting large area device available for photovoltaic power generation is maximized. Also disclosed herein are methods for the manufacture of the improved device.

Abstract: A method of depositing a semiconductor alloy film onto a substrate by activating groups of free radicals and incorporating desired ones of the activated groups into the film.

Abstract: A p-doped microcrystalline silicon alloy material incorporated into a tandem photovoltaic device.

Abstract: An improved cathode assembly specifically designed to provide for the uniform, localized profiling of dopant or other alterant elements into the host matrix of a semiconductor alloy material which is continuously and uniformly deposited onto a moving substrate by a glow discharge deposition process.

Abstract: A vertical processor for the continuous deposition of semiconductor alloy material by glow discharge techniques. The vertical processor includes a plurality of operatively interconnected deposition chambers, at least one chamber of which includes a generally vertical cathode plate about each of the opposed faces of which a plasma region is developed and a substrate continuously passes for the deposition of semiconductor alloy material thereonto. Through the utilization of the vertical deposition scenario, the length of the processor may be substantially foreshortened, power consumption may be substantially decreased and feedstock gases may be more efficiently utilized.

Abstract: A fluorinated, p-doped microcrystalline semiconductor alloy material; electronic devices incorporating said p-doped material; and the method for fabricating said p-doped material.

Abstract: Apparatus for microwave energized glow discharge deposition of materials, onto a substrate including electronic structures having a plurality of layers of amorphous semiconducting alloys of varying conductivity types. The apparatus includes at least one deposition chamber in which a novel antenna coupled to a source of microwave energy to form a microwave energy excited glow discharge plasma is disposed. The antenna has coaxial conductors approximately one half wavelength long that are electrically connected to each other at their respective distal ends. A multiple integer of one half wavelength of a coaxial transmission line coupling the antenna energy and source may also form part of the antenna. The respective outer conductors of the transmission line and antenna are separated by an electrically small gap, but the respective center conductors are electrically connected.

Abstract: An improved photovoltaic device characterized by long term stability in its photoconversion ability. The device is adapted to absorb incident light throughout a substantial portion of the bulk of the photoactive region thereof in a substantially uniform manner. Said uniform absorption of light is provided by grading the band gap of at least a portion of the semiconductor material of the photoactive region thereof such that the graded portions most proximate the light incident surface of the photovoltaic device have a wider band gap than do those portions more distal from the light incident surface. The band gap gradation may be smooth or stepped, and may be accomplished by compositional variation of the semiconductor materials forming the photoactive region. A method for fabricating the stable photovoltaic device of the instant invention is also provided.

Abstract: A valve for isolating the interior of a glow discharge chamber from the atmosphere and other reactants. The valve includes a body mounted in an aperture of the chamber. A slit-like opening is provided therein to allow the interior of the chamber to communicate with interrelated elements of a deposition system. A source is provided for introducing inert gas into the opening under pressure somewhat greater than that of reaction gases and plasma within the chamber to create an effective, non-reactive gas curtain.

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: A continuous system for depositing at least one layer of amorphous semiconductor material upon a substrate. Feed and takeup sections provide reel-to-reel advancement of a thin film substrate through the system. At least one chamber is located between the feed and takeup sections. A plasma is generated therein by glow discharge decomposition of an appropriate mixture of reaction gases. Apparatus associated with the chamber allows the close regulation of the plasma/substrate surface equilibrium to assure the deposition of a uniform layer of amorphous material. At least one servocontrolled reel drive regulates the tension of the web-like substrate as it advances to avoid cracking and to assure its proper registration with a mask comprising a plurality of strips. A curtain of inert gas provides isolation between the interior of each chamber and the environment.

Abstract: A method for introducing sweep gas through a baffle system adapted for use with glow discharge deposition apparatus in which successive amorphous semiconductor layers are deposited on a substrate. The deposition apparatus includes at least a pair of adjacent dedicated deposition chambers into each of which different process gases are introduced, the chambers being operatively connected by a gas gate. Inert gases are swept through the gas gate to minimize back diffusion of process gases from the chambers. The baffle system is adapted to prevent said sweep gases from entering into turbulent flow when traveling through the gas gate passageway. Further, a sufficient volume per unit time of sweep gas is introduced to insure that some sweep gas flows into the cathode region of the first chamber, thereby substantially preventing process gases and plasma from escaping from the cathode region and forming silane powder.

Abstract: The production of improved photoresponsive amorphous alloys and devices, such as photovoltaic, photoreceptive devices and the like; having improved wavelength threshold characteristics is made possible by adding one or more band gap adjusting elements to the alloys and devices. The adjusting element or elements are added at least to the active photoresponsive regions of amorphous devices containing silicone and fluorine, and preferably hydrogen. One adjusting element is germanium which narrows the band gap from that of the materials without the adjusting element incorporated therein. Other adjusting elements can be used such as tin. The silicon and adjusting elements are concurrently combined and deposited as amorphous alloys by vapor deposition, sputtering or glow discharge decomposition. The addition of fluorine bonding and electronegativity to the alloy acts as a compensating or altering element to reduce the density of states in the energy gap thereof.

Abstract: An apparatus and process utilizes microwave energy for depositing amorphous alloy materials in layered form onto a receiving surface. The process results in materials having unique properties suitable for many applications including photovoltaic applications. The process includes the steps of providing at least one source of microwave energy, providing at least two reaction gases, each gas containing at least one alloying element to be deposited onto the receiving surface, and selectively exciting the reaction gases with microwave energy to create excited species containing the alloying elements to be deposited for depositing the alloys in alternating layers onto the receiving surface. For depositing alternating layers of silicon and germanium alloys, the reactions gases can include silane (SiH.sub.4) or silicon tetrafluoride (SiF.sub.4), and germane (GeH.sub.4) or germanium tetrafluoride (GeF.sub.4).

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: An amorphous semiconductor body, most advantageously a glow discharge deposited silicon-containing host matrix film, is provided containing at least fluorine as a compensating or altering agent, and most preferably at least one complementary compensating or altering agent, such as hydrogen, both of which reduce the localized defect states in the energy gap of the amorphous semiconductor material to a degree which either one alone could not achieve. The silicon and/or other elements of the host matrix film are deposited by the glow discharge decomposition of gaseous compounds preferably with fluorine as one element of a compound, the hydrogen and other compensating and altering material being preferably a molecular gas or an element of a compound of silicon or other host matrix element.

Abstract: Designed tailormade nonequilibrium synthetic disordered materials are provided containing nonperiodically distributed local environments whose position and type are controlled to obtain specific properties which can be coupled or decoupled one from another and collectively from the constraints implied by an ordered structure. Atoms or groups of atoms can be placed in the matrix in specific designed positions to compensate the spins to obtain unusual physical and chemical properties. The compositional variation which produces the required nonequilibrium "multi-disordered" materials is accomplished by selectively depositing desired atoms and groups of atoms into designed locations to permit the construction of a true three-dimensionally engineered material. Where order is an engineering need, it can be designed in a local scale or interspersed in varying amounts including layers through the material to create new material functions.

Abstract: A process for making amorphous semiconductor alloy films and devices at high deposition rates utilizes microwave energy to form a deposition plasma. The alloys exhibit high quality electronic properties suitable for many applications including photovoltaic applications.The process includes the steps of providing a source of microwave energy, coupling the microwave energy into a substantially enclosed reaction vessel containing the substrate onto which the amorphous semiconductor film is to be deposited, and introducing into the vessel reaction gases including at least one semiconductor containing compound. The microwave energy and the reaction gases form a glow discharge plasma within the vessel to deposit an amorphous semiconductor film from the reaction gases onto the substrate. The reactions gases can include silane (SiH.sub.4), silicon tetrafluoride (SiF.sub.4), silane and silicon tetrafluoride, silane and germane (GeH.sub.4), and silicon tetrafluoride and germane.

Abstract: An apparatus for manufacturing photovoltaic devices of the type including a plurality of layers of semiconductor materials deposited onto a substrate includes a plurality of deposition chambers, each chamber arranged to deposit a respective one of the layers of semiconductor materials onto the substrate as the substrate is advanced therethrough. At least one of the deposition chambers is coupled to a source of microwave energy to form a microwave energy excited glow discharge plasma within the at least one deposition chamber for depositing at least one of the layers of semiconductor material onto the substrate from the microwave energy excited glow discharge plasma within the at least one deposition chamber.Also disclosed is an assembly for depositing a material onto a substrate from a microwave energy excited plasma. The assembly includes a deposition chamber, a source of microwave energy, and an antenna extending into the chamber and coupled to the microwave energy source.

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.