Siemens Aktiengesellschaft

Josef Grabmaier

Richard Falckenberg

Hubert Aulich

Helmut Foell

Wolfgang Kruehler

Gerhard Hoyler

Nikolaos Douklias

Bernhard Freienstein

Hartmut Schneider

Christa Grabmaier

Karl-Heinz Eisenrith

Heinz Hacker

Rolf Plaettner

Hans Pink

Arthur Endroes

Karl Geim

Juergen Schneider

Helmut Foll

Lore Bernewitz

Otmar Hintringer

A new solar cell of a I-III-VI.sub.2 semiconductor material that has an inversion layer is provided. The cell comprises a substrate having an electrically conductive, first electrode, a p-conductive, polycrystalline semiconductor layer of chalcopyrite material, a barrier layer composed of an electrically non-conductive material, a second electrode, and an antireflection layer. The anti-reflection layer has stationary, positive charges that induce a negatively charged inversion layer in the boundary surface region of the semiconductor layer relative to the barrier layer. The negatively charged inversion layer serves as an emitter for a space charge zone. In an embodiment the invention comprises a semiconductor layer of copper-indium-diselenide or copper-gallium-diselenide, a barrier layer of silicon dioxide, an anti-reflection layer of silicon nitride, and cesium chloride as the stationary charges.

Induced junction chalcopyrite solar cell

For the continuous melting of silicon granulate for a band drawing method, a melt reservoir in communication with the melt crucible based on the principle of communicating vessels, is provided in the form of a thermally insulated, annular crucible in whose center axis a rotary plate to be centrifugally accelerated is arranged, the speed thereof being continuously varied. Two pipe parts connected to one another at an angle between approximately 45.degree. to about 90.degree. are secured on the rotary plate, the one, vertical pipe part thereof serving as admission in the rotational axis and the other pipe part thereof forming the acceleration path for the granulate particles in the direction toward the annular melt crucible. On the basis of this arrangement, a uniform delivery and melting of the granulate particles in the melt surface is achieved and, thus, a continuous silicon band drawing with uniform layer thickness is enabled. The arrangement is used in the manufacture of silicon bands for solar cells.

Arrangement for the continuous melting of granulated silicon for a

A method and device for the complete emptying of flat quartz tanks or crucibles filled with silicon melt is provided. The apparatus includes an open outlet nozzle located in a floor of the tank and a tube-shaped, rod-shaped, or channel-shaped member composed of a material that is well-wettable by silicon melt that is brought into contact with the outlet nozzle after the conclusion of the drawing process. The member is in fluid communication with a collecting vessel. The outlet nozzle is so constructed and arranged that the silicon melt adjacent at the nozzle aperture is prevented from running out during the band drawing due to the curvature pressure of its downwardly, convexly arced surface. The apparatus can be used in continuous, horizontal band-drawing of silicon for solar cells.

Arrangement for the complete emptying of quartz tanks or crucibles

A tandem solar module and a method for the manufacture thereof. The tandem solar module has a first, large-area, lower solar sub-module of polycrystalline silicon (c-Si), has an electrically insulating, transparent intermediate layer functioning as an optical coupler, and also has a second, transparent, upper sub-module of amorphous, hydrogenated silicon (a-Si:H). Both sub-modules are provided with mutually independent electrical contacts and each is functional in and of itself. An active material in the first sub-module that is preferably structured strip-shaped can be composed of silicon strips produced in a band drawing method. The second sub-module is executed in thin-film technology in a known way and has a p-i-n structure. Its substrate serves as a covering for the overall module. The tandem solar module exhibits high efficiency and is cost-effective to be manufactured. It can be manufactured with a large-area and exhibits high long-term stability.

Method of making tandem solar cell module

A method and apparatus for producing disk-shaped or wafer-shaped silicon bodies from a silicon tape produced in a horizontal tape-drawing process, utilizing a woven fabric of graphite threads as a carrier for the silicon to be crystallized. The crystallization of the molten silicon is initiated by heating sources positioned about the melt crucible. Radiation losses are reduced by providing shielding members in predetermined, prescribed intervals corresponding to the areas at which the parting lines are to be provided in the tape. The shielding members reduce the radiation losses to such an extent that a readily frangible line is produced in the area of the shielding members enabling the tape to be broken up at regular, predetermined intervals on a continuous basis.

Apparatus for parting wafer-shaped silicon bodies, useful for solar

A method for horizontal silicon tape drawing is provided which can be practiced at a high drawing speed. The carrier member uses parallel threads of a material having a higher emission factor .epsilon. than the emission factor of molten silicon and such threads serve as crystallization nucleators for silicon. A silicon melt tank is used which has a length l that is at least as long as the contacting length existing between the surface of molten silicon and the horizontally moving threads so that L=V.sub.z .multidot.t where v.sub.z is the drawing speed and t is the dwell time. The drawing direction d.sub.z is set inclined at an angle .alpha..ltoreq. 10.degree. relative to the horizontal. Radiant losses from the silicon melt surface are regulated by reflectors. The method provides the possibility of manufacturing tape-shaped silicon crystals 16 for solar cells with a constant thickness and width.

Method and apparatus for manufacturing tape-shaped silicon crystals with

A method for manufacturing crack-free, large-surface silicon crystal bodies for solar cells wherein a carrier member composed of a carbon fiber fabric is coated with silicon by bringing a molten silicon into contact with the carrier member and crystallizing it. In order to improve the wettability, the carrier member is subjected to an activating surface treatment before the coating. The method is useful for continuous manufacture of silicon sheets for solar cells.

Carbon fiber substrate pretreatment for manufacturing crack-free,

A method for the manufacture of gallium arsenide thin film solar cells on inexpensive substrate material whereby an intermediate layer of highly doped, amorphous germanium is employed in order to promote the growth of the gallium arsenide layers. A high-energy radiation is directed to specific, prescribed points on the highly doped, amorphous germanium layer thereby generating centers having a defined crystal orientation, so that the epitaxial layer spreads laterally from these centers in a surface-covering fashion during the epitaxial vapor phase deposition. The solar cells produced by designational grain growth can be manufactured with high purity in a simple way and have an efficiency (greater than 20%) comparable to known mono-crystalline solar cells.

Method for the manufacture of gallium arsenide thin film solar cells

An improved method of forming porous glass preforms by generating glass particles from a vapor phase and applying the particles onto a substrate characterized by generating the glass particles from a vapor phase in a separate operation, collecting the particles and then subsequently applying the previously collected particles onto a deposition surface of the substrate by creating a hot zone adjacent the deposition surface and projecting the particles as a stream through the hot zone and onto the deposition surface.

Method for manufacturing preforms of glass for optical fibers

Starting plate-like silicon bodies matched to the dimensions desired in a product silicon crystal bodies are melted and then crystallized on a horizontal carrier member having a net structure using a heater arrangement. The carrier member is substantially not wettable by molten silicon and preferably consists of a quartz glass fiber fabric and is removable after the crystallization. The method is useful for the manufacture of silicon for solar cells and prevents contaminants from the carrier member from being incorporated into the product silicon crystal body and thereby deteriorating the electrical properties of the solar cells.

Method for making large-surface silicon crystal bodies

A method and an apparatus is provided for the manufacture of large-area silicon crystal bodies useful for solar cells. A carrier member consisting of a net-like graphite fabric or quartz fabric is moved horizontally through a heater arrangement carrying silicon plates on its surface which are matched to the dimensions of the carrier member. The silicon body is caused to melt and the molten silicon fills in the meshes of the net after which crystallization is induced. Meshes having dimensions up to about 10 mm.times.10 mm are thus filled with silicon. The technique involves low production costs and high product crystal quality and serves for the continuous manufacture of silicon ribbons for solar cells.

Method large-area silicon bodies

Apparatus for the manufacture of large-surfaced, band-shaped silicon bodies for solar cells through a continuous layering process which uses a net-like structured graphite carrier unit. The net-like structure is used in conjunction with a melting pot made from graphite for receiving silicon smelt. The smelt is fed via a drain opening provided in the floor section of the melting pot to the carrier unit guided through a canal which has been arranged in horizontal direction below the melting pot. In order to ensure a continuous replacement of the smelt volume in the layering canal, the canal is shaped in downward direction as a shallow basin made from quartz, whereby the basin areas 'a' and 'b' are of different depth. In this manner, a 'reserve volume' is provided, which ensures a uniform layering. The apparatus allows a continuous production of silicon bands for solar cells.

Apparatus for manufacturing large-surface, band-shaped silicon for solar

In an exemplary embodiment, tape-shaped silicon bodies for solar cells are formed by continuous coating of a carrier body having a mesh structure. A melt bath receives the silicon melt and has a floor part with capillary openings therein for supplying the melt, the capillary openings leading perpendicularly toward the exterior of the vat and proceeding parallel to one another, and wherein a channel for the guidance of the carrier body proceeding in a horizontal direction is disposed below the melt vat in the region of the capillary openings. The guide channel for the carrier body can also be disposed above a body with capillaries proceeding parallel in a vertical direction, the body being partially immersed in the vat containing the silicon melt for the purpose of supplying the melt via the capillaries. The devices enable continuous tape drawing from a silicon melt wherein convection currents are avoided in the melt.

Device for manufacturing large-surface, tape-shaped silicon bodies for

This invention involves a method and apparatus for drawing crystalline bodies from a melt by means of an open-ended drawing nozzle which determines the cross-sectional geometry of the crystalline body. The drawing nozzle is composed of a material which is resistant to the melt. The feed of melt proceeds from a reservoir situated at the lower end of the drawing nozzle and the melt is conveyed to the upper opening thereof by capillary action. In keeping with the present invention, there is provided a drawing nozzle which has an upper opening merging into a contoured surface such that the meniscus formed at the interface between the crystalline and molten phases is freely displaceable on the contoured surface into which the upper opening discharges.

Method and apparatus for drawing crystalline bodies from a melt

An improved large surface, quasi-monocrystalline silicon crystal bodies of the type used in solar cells. The bodies are produced by reacting at least the surface of a carbon fiber fabric with molten silicon under conditions of temperature and viscosity sufficient to cause the molten silicon to penetrate the fabric and produce silicon carbide at at least the surface of the fibers, and immediately thereafter coating the thus reacted fabric with metallic silicon from a second molten silicon bath to produce a silicon coating.

Growing community of inventors

Berg, Germany

Josef Grabmaier