Patents by Inventor Helmut Foell
Helmut Foell has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 9716276Abstract: An electrode for lithium ion batteries, the electrode having a metal film which is inert to lithium ions and having a plurality of silicon nanowires protruding from the film, which are arranged on at least one flat side of the film, wherein sections of the nanowires are enclosed by the metal film.Type: GrantFiled: January 3, 2016Date of Patent: July 25, 2017Assignee: SAMSUNG ELECTRONICS CO., LTD.Inventors: Joerg Bahr, Juergen Carstensen, Helmut Foell, Oliver Riemenschneider, Hauke Hartz, Emmanuel Ossei-Wusu
-
Publication number: 20160118643Abstract: An electrode for lithium ion batteries, the electrode having a metal film which is inert to lithium ions and having a plurality of silicon nanowires protruding from the film, which are arranged on at least one flat side of the film, wherein sections of the nanowires are enclosed by the metal film.Type: ApplicationFiled: January 3, 2016Publication date: April 28, 2016Inventors: Joerg Bahr, Juergen Carstensen, Helmut Foell, Oliver Riemenschneider, Hauke Hartz, Emmanuel Ossei-Wusu
-
Patent number: 9246159Abstract: An electrode for lithium ion batteries, the electrode having a metal film which is inert to lithium ions and having a plurality of silicon nanowires protruding from the film, which are arranged on at least one flat side of the film, wherein sections of the nanowires are enclosed by the metal film.Type: GrantFiled: July 9, 2010Date of Patent: January 26, 2016Assignee: SAMSUNG ELECTRONICS CO., LTD.Inventors: Joerg Bahr, Juergen Carstensen, Helmut Foell, Oliver Riemenschneider, Hauke Hartz, Emmanuel Ossei-Wusu
-
Patent number: 8829938Abstract: A measuring method and device for characterizing a semiconductor component (1) having a pn junction and a measuring surface, which has a contacting subarea, covered by a metallization. The method including: A. Planar application of electromagnetic excitation radiation onto the measuring area of the semiconductor component (1) for separating charge carrier pairs in the semiconductor component (1), and B. spatially resolved measurement of electromagnetic radiation originating from the semiconductor component (1) using a detection unit. In one step A, a predetermined excitation subarea of the measuring surface has a predetermined intensity of the excitation radiation and at least one sink subarea of the measuring surface has an intensity of the excitation radiation which is less than the intensity applied to the excitation subarea. The excitation and sink subareas are disposed on opposite sides of said contacting subarea and adjoin it and/or entirely or partially overlap it.Type: GrantFiled: February 23, 2009Date of Patent: September 9, 2014Assignees: Fraunhofer-Gesellschaft zur Föderung der angewandten Forschung e.V., Christian-Albrechts-Universität zu Kiel, Albert-Ludwigs-Universität FrieburgInventors: Jürgen Carstensen, Andreas Schütt, Helmut Föll, Wilhelm Warta, Martin Kasemann
-
Patent number: 8580102Abstract: Method for the electrochemical etching of macropores in n-type silicon wafers, using illumination of the wafer reverse sides and using an aqueous electrolyte, characterized in that the electrolyte is an aqueous acetic acid solution with the composition of H2O:CH3COOH in the range between 2:1 and 7:3, with an addition of at least 9 percent by weight hydrofluoric acid.Type: GrantFiled: February 28, 2009Date of Patent: November 12, 2013Assignee: Christian-Albrechts-Universitaet zu KielInventors: Emmanuel Ossei-Wusu, Ala Cojocaru, Juergen Carstensen, Helmut Foell
-
Publication number: 20120164529Abstract: An electrode for lithium ion batteries, the electrode having a metal film which is inert to lithium ions and having a plurality of silicon nanowires protruding from the film, which are arranged on at least one flat side of the film, wherein sections of the nanowires are enclosed by the metal film.Type: ApplicationFiled: July 9, 2010Publication date: June 28, 2012Applicant: CHRISTIAN-ALBRECHTES-UNIVERSITAT ZU KIELInventors: Joerg Bahr, Juergen Carstensen, Helmut Foell, Oliver Riemenschneider, Hauke Hartz, Emmanuel Ossei-Wusu
-
Publication number: 20110294302Abstract: Method for the electrochemical etching of macropores in n-type silicon wafers, using illumination of the wafer reverse sides and using an aqueous electrolyte, characterized in that the electrolyte is an aqueous acetic acid solution with the composition of H2O: CH3COOH in the range between 2:1 and 7:3, with an addition of at least 9 percent by weight hydrofluoric acid.Type: ApplicationFiled: February 28, 2009Publication date: December 1, 2011Applicant: CHRISTIAN-ALBRECHTS-UNIVERSITAET ZU KIELInventors: Emmanuel Ossei-Wusu, Ala Cojocaru, Juergen Carstensen, Helmut Foell
-
Patent number: 7208069Abstract: The device etches semiconductors with a large surface area in a trough-shaped receptacle containing a liquid electrolyte. A sample head is mounted inside the etching trough, and is provided with a device for holding at least one semiconductor wafer. The device is tilted to promote turbulent electrolyte flow in a space between a bottom surface of the semiconductor wafer and top surface of the trough-shaped receptacle.Type: GrantFiled: July 24, 2003Date of Patent: April 24, 2007Assignee: Kiel UniversityInventors: Marc Christophersen, Jörg Bahr, Jürgen Carstensen, Kay Steen, Georgi Popkirov, Helmut Föll
-
Patent number: 5209833Abstract: A semiconductor crystal wafer is fixed between two electrolyte-filled cells so that the front surface and rear surface thereof are respectively in contact with an electrolyte. A respective electrode is located in the electrolyte, a DC voltage being applied between these electrodes so that the semiconductor-to-electrolyte contact of the one cell is polarized in the conducting direction and the other is polarized in the non-conducting direction. A current flow through the semiconductor crystal body is enabled in that the inhibiting surface of the semiconductor crystal is illuminated and charge carriers are generated as a result thereof. On the basis of the selection of suitable electrolytes and the intensity of illumination, high current density is possible even given high-impedance semiconductor crystal wafers as well as semiconductor crystal bodies having doping steps or pn junctions. The method is particularly simple in many semiconductor processing and analyses methods.Type: GrantFiled: May 22, 1990Date of Patent: May 11, 1993Assignee: Siemens AktiengesellschaftInventors: Helmut Foell, Volker Lehmann
-
Patent number: 5130643Abstract: For a two-stage measuring method, a respective cell having an electrode therein is applied to the front surface and to the rear surface of a semiconductor wafer, whereby only the cell as the rear surface is filled with an electrolyte in the first measuring step. The minority carrier photo current I.sub.2 ' flowing between the electrode and the semiconductor surface in the rear cell, given illumination of the front cell of the semiconductor crystal wafer, is dependent on the recombination speed S at the front surface. In the second measuring step, the front cell is also filled with electrolyte and both the rear surface photo current I.sub.2, given what is now a negligible influence of the value S as well as the front surface photo current I.sub.1 are measured. The recombination speed S can be calculated from the measure photo currents with the assistance of a mathematical equation.Type: GrantFiled: November 26, 1990Date of Patent: July 14, 1992Assignee: Siemens AktiengesellschaftInventors: Helmut Foell, Volker Lehmann
-
Patent number: 5128514Abstract: The black radiator contains a doped, crystalline silicon member having a honeycombed surface and contains a controllable electrical heating mechanism with which the silicon member can be heated. The heating mechanism has a heating coil that is a doped silicon structure that is oppositely doped to the doping of the silicon member and to which a controllable voltage is applied. The manufacturing method provides that the silicon member having a honeycombed surface be manufactured from an n-silicon member by electrolytic etching.Type: GrantFiled: June 29, 1988Date of Patent: July 7, 1992Assignee: Siemens AktiengesellschaftInventors: Volker Lehmann, Helmut Foell
-
Patent number: 5010294Abstract: The measurement of the diffusion length of minority charge carriers in a semiconductor crystal body is enabled in that the front side and the rear side of the crystal wafer are each respectively brought into contact with an electrolyte in a respective measuring cell and an inhibiting space charge zone is generated at the front side of the wafer. The front side is irradiated with light having a wave length of .lambda.>800 nm and the front side photocurrent I.sub.1 of the minority charge carriers thereby generated is measured. The diffusion length L can be calculated from the photocurrent I.sub.1 with the assistance of a mathematical equation. The topical distribution of the diffusion length L is obtained given point-by-point irradiation and scanning over the crystal wafer. Diffusion lengths of L<150 .mu.m can be measured by selecting a light source having a wave length of .lambda.>800 nm.Type: GrantFiled: May 11, 1990Date of Patent: April 23, 1991Assignee: Siemens AktiengesellschaftInventors: Helmut Foell, Volker Lehmann
-
Patent number: 4874484Abstract: The present invention provides the production of apertured openings or trenches in layers or substrates composed of n-doped silicon proceeding in an electrolytic way, whereby the silicon is connected as a positively polarized electrode of an electrolysis cell containing an agent that contains hydrofluoric acid. Hole structures having highly variable cross-section can be reproducibly manufactured with the method of the invention and holes can be localized by prescribing nuclei. The invention can be used in the manufacture of trench cells in memory modules, insulating trenches in LSI semiconductor circuits, large-area capacitors (varicaps), and in contacting more deeply disposed layers in disconnectable and voltage-controlled thyristors.Type: GrantFiled: May 13, 1988Date of Patent: October 17, 1989Assignee: Siemens AktiengesellschaftInventors: Helmut Foell, Volker Lehmann
-
Patent number: 4841239Abstract: Method and measuring instrument for identifying the diffusion length of minority charge carriers for non-destructive detection of flaws and impurities in semiconductor crystal bodies. The method provides that the semiconductor crystal body is positioned between two electrolyte-filled measuring chamber halves and that the minority charge carriers of the photocurrent that results at a front side of the semiconductor crystal body due to irradiation is detected by an applied constant voltage between a backside of the semiconductor crystal body and a rear electrolyte at the backside of the semiconductor crystal body. Taking the thickness (D) of the semiconductor crystal body into consideration, the diffusion length (L) can be calculated from a mathematical equation using the quotient of the minority charge carrier current I.sub.G I/.sub.O occurring at the backside and at the front side of the semiconductor crystal body.Type: GrantFiled: May 20, 1988Date of Patent: June 20, 1989Assignee: Siemens AktiengesellschaftInventors: Helmut Foell, Volker Lehmann
-
Patent number: 4563976Abstract: 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.Type: GrantFiled: July 11, 1983Date of Patent: January 14, 1986Assignee: Siemens AktiengesellschaftInventors: Helmut Foell, Josef Grabmaier, Richard Falckenberg
-
Patent number: 4557793Abstract: 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.Type: GrantFiled: January 25, 1984Date of Patent: December 10, 1985Assignee: Siemens AktiengesellschaftInventors: Helmut Foell, Josef Grabmaier, Juergen Schneider
-
Patent number: 4505221Abstract: Apparatus and method for asymmetrically coating a tape-shaped carrier body with crystallized silicon for further processing into solar cells. In an exemplary embodiment a carrier body in the form of a graphite mesh is to be drawn through a guide channel leading from the floor of a melt vat and is moistened by the melt. The silicon is caused to crystallize above the melt vat because of a temperature gradient generated at right angles relative to the path of the coated carrier body. The temperature gradient can, for example, be produced by means of single-sided heating, or by a plate-shaped body extending from the melt parallel to the carrier body, or by guide lips with upper boundaries exhibiting different heights and widths. The method and apparatus serve for the continuous manufacture of silicon tapes for solar cells.Type: GrantFiled: July 11, 1983Date of Patent: March 19, 1985Assignee: Siemens AktiengesellschaftInventors: Richard Falckenberg, Helmut Foell, Josef Grabmaier
-
Patent number: 4481235Abstract: A method and apparatus for manufacturing tape-shaped silicon bodies for solar cells wherein a tape-shaped reticulate carrier is passed vertically downwardly through a drawing nozzle including a slot which is full of molten silicon. The drawing nozzle is located above the level of molten silicon in a vat containing such molten silicon, and capillary means are provided to deliver the molten silicon from the vat into the drawing nozzle to fill the same with the molten silicon.Type: GrantFiled: September 13, 1983Date of Patent: November 6, 1984Assignee: Siemens AktiengesellschaftInventors: Helmut Foell, Bernhard Freienstein, Karl Geim, Josef Grabmaier, Otmar Hintringer