Patents by Inventor Uwe Sahr

Uwe Sahr 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: 8101019
    Abstract: In the method of making a monocrystalline or polycrystalline semiconductor material semiconductor raw material is introduced into a melting crucible and directionally solidified using a vertical gradient freeze method. The molten material trickles downward, so that the raw material that has not yet melted gradually slumps in the melting crucible. The semiconductor raw material is replenished from above onto a zone of semiconductor raw material which has not yet melted or is not completely melted to at least partly compensate for shrinkage of the raw material and to raise the filling level. To reduce the melting time and influence the thermal conditions in the system as little as possible, the semiconductor raw material to be replenished is heated to a temperature below its melting temperature and introduced into the crucible in the heated state.
    Type: Grant
    Filed: December 15, 2008
    Date of Patent: January 24, 2012
    Assignee: Schott AG
    Inventors: Uwe Sahr, Matthias Mueller, Ingo Schwirtlich, Frank-Thomas Lentes, Frank Buellesfeld
  • Publication number: 20110309555
    Abstract: A method is proposed for the solidification of a non-metal melt (130) which is located in a crucible (120) arranged in the device (100), wherein the device (100) has a multiplicity of inductors (100) for the creation of magnetic fields. By feeding in a first set of phase-displaced alternating currents (I1a, I2b, I3c, I4d) having a first frequency (f1), a first travelling field (W1) is created in the melt (130). By feeding in at least one second set of phase-displaced alternating currents (I2a, I2b, I3c, I4d) having a second frequency (f2), a second travelling field (W2) is created in the melt (130) which is directed against the first travelling field (W1), wherein the inductors (100) are arranged on the crucible (120) in a vertically extending arrangement, so that the alternating fields created (W1, W2) pass through the melt (130) in vertical direction (Y) and have a flow force minimum on the crucible or vessel wall.
    Type: Application
    Filed: November 12, 2009
    Publication date: December 22, 2011
    Applicants: FORSCHUNGSVERBUND BERLIN E.V., SCHOTT SOLAR AG
    Inventors: Frank Bullesfeld, Uwe Sahr, Wolfram Miller, Peter Rudolph, Uwe Rehse, Natascha Dropka
  • Patent number: 7811383
    Abstract: The device for production of a monocrystalline or a multicrystalline material blank, especially a silicon multicrystalline blank, using the VGF method has a crucible with a rectangular or square cross section. A flat heating device, especially a jacket heater, which generates an inhomogeneous temperature profile, is arranged around the crucible. This temperature profile corresponds to the temperature gradient formed in the center of the crucible. The heat output of the flat heating device decreases from the top to the bottom end of the crucible. The flat heating device includes parallel heating webs, which extend in a meandering course. The heat outputs from the heating webs differ according to their different conductor cross sections. To avoid local overheating in corner areas of the crucible, constrictions of the cross sections of the heating webs are provided at inversion zones of their meandering course.
    Type: Grant
    Filed: April 9, 2009
    Date of Patent: October 12, 2010
    Assignee: Schott AG
    Inventors: Matthias Mueller, Markus Finkbeiner, Uwe Sahr, Ingo Schwirtlich, Michael Clauss
  • Patent number: 7597756
    Abstract: The method of producing monocrystalline or multicrystalline blanks, especially silicon blanks, by using a vertical-gradient-freeze method, includes providing a crucible with a rectangular or square-shaped cross section and a heating jacket disposed around the crucible, which has a number of flat heating elements with a meandering course disposed on side faces of the crucible. The heating jacket generates an inhomogeneous temperature profile corresponding to a temperature gradient in the center of the crucible. The flat heating elements preferably comprise parallel heating webs, whose heat output is set by varying the conductor cross section. To avoid local overheating in corner areas of the crucible, constrictions of the cross section are provided at inversion zones of the meandering courses of the webs. The flat heating elements can be formed from a plurality of interconnected individual segments.
    Type: Grant
    Filed: March 27, 2007
    Date of Patent: October 6, 2009
    Assignee: Schott AG
    Inventors: Matthias Mueller, Markus Finkbeiner, Uwe Sahr, Ingo Schwirtlich, Michael Clauss
  • Publication number: 20090188427
    Abstract: The device for production of a monocrystalline or a multicrystalline material blank, especially a silicon multicrystalline blank, using the VGF method has a crucible with a rectangular or square cross section. A flat heating device, especially a jacket heater, which generates an inhomogeneous temperature profile, is arranged around the crucible. This temperature profile corresponds to the temperature gradient formed in the center of the crucible. The heat output of the flat heating device decreases from the top to the bottom end of the crucible. The flat heating device includes parallel heating webs, which extend in a meandering course. The heat outputs from the heating webs differ according to their different conductor cross sections. To avoid local overheating in corner areas of the crucible, constrictions of the cross sections of the heating webs are provided at inversion zones of their meandering course.
    Type: Application
    Filed: April 9, 2009
    Publication date: July 30, 2009
    Inventors: Matthias Mueller, Markus Finkbeiner, Uwe Sahr, Ingo Schwirtlich, Michael Clauss
  • Publication number: 20090158993
    Abstract: The invention relates to a method for producing a monocrystalline or polycrystalline semiconductor material by way of directional solidification, wherein lumpy semiconductor raw material is introduced into a melting crucible and melted therein and directionally solidified, in particular using the vertical gradient freeze method. In order to prevent contamination and damage, the semiconductor raw material is melted from the upper end of the melting crucible. The molten material trickles downward, so that semiconductor raw material which has not yet melted gradually slumps in the melting crucible. In this case, the additional semiconductor raw material is replenished to the melting crucible from above onto a zone of semiconductor raw material which has not yet melted or is not completely melted, in order at least partly to compensate for a volumetric shrinkage of the semiconductor raw material and to increase the filling level of the crucible.
    Type: Application
    Filed: December 15, 2008
    Publication date: June 25, 2009
    Inventors: Uwe Sahr, Matthias Mueller, Ingo Schwirtlich, Frank-Thomas Lentes, Frank Buellesfeld
  • Publication number: 20090047203
    Abstract: The invention relates to the production of bulky monocrystalline metal or semi-metal bodies, in particular of a monocrystalline Si ingot, using the vertical gradient freeze (VGF) method by directional solidification of a melt in a melting crucible having a polygonal basic shape. According to the invention, the entire bottom of the melting crucible is completely covered with a thin seed crystal plate made of the monocrystalline semi-metal or metal. Throughout the procedure, the bottom of the melting crucible is kept below the melting temperature of the semi-metal or metal in order to prevent melting of the seed crystal plate. Monocrystalline ingots produced in this way are distinguished by a low average dislocation density of for example less than 105 cm?2, allowing the production of very efficient monocrystalline Si solar cells.
    Type: Application
    Filed: August 14, 2008
    Publication date: February 19, 2009
    Inventors: Matthias Mueller, Uwe Sahr
  • Publication number: 20070266931
    Abstract: The invention relates to a device and a method for the production of monocrystalline or multicrystalline materials using the vertical-gradient-freeze method, in particular silicon for applications in photovoltaics. According to the invention a low amount of wastage is achieved in that the cross section of the crucible is polygonal, in particular rectangular or square-shaped. Disposed around the circumference of the crucible there is a flat or planar heating element, in particular a jacket heater, which generates an inhomogeneous temperature profile. This corresponds to the temperature gradient formed in the centre of the crucible. The heat output of the flat heating element decreases going from the top end to the bottom end of the crucible. The flat heating element comprises a plurality of parallel heating webs, extending in a vertical or horizontal meandering course. The heat output from the webs is set by varying the conductor cross section.
    Type: Application
    Filed: March 27, 2007
    Publication date: November 22, 2007
    Inventors: Matthias Mueller, Markus Finkbeiner, Uwe Sahr, Ingo Schwirtlich, Michael Clauss