Calisolar Inc.

Other

Silicor Materials Inc.

Jenoptik Polymer Systems Gmbh

Jenoptik Optical Systems Gmbh

Vera Abrosimova

Kamel Ounadjela

Fritz Kirscht

Matthias Heuer

Dieter Linke

Jean Patrice Rakotoniana

Martin Kaes

Jean Patrice Rakotoniaina

Anis Jouini

Bernd Kloth

Torsten Trenkler

Techniques for the formation of a silicon ingot using a low-grade silicon feedstock include forming within a crucible device a molten silicon from a low-grade silicon feedstock and performing a directional solidification of the molten silicon to form a silicon ingot within the crucible device. The directional solidification forms a generally solidified quantity of silicon and a generally molten quantity of silicon. The method and system include removing from the crucible device at least a portion of the generally molten quantity of silicon while retaining within the crucible device the generally solidified quantity of silicon. Controlling the directional solidification of the generally solidified quantity of silicon, while removing the more contaminated molten silicon, results in a silicon ingot possessing a generally higher grade of silicon than the low-grade silicon feedstock.

Method and system for forming a silicon ingot using a low-grade silicon feedstock

The invention is directed to a surface emitting semiconductor light-emitting diode (LED) in which a reflector layer () of the first conductivity type is provided between a substrate () and a first barrier layer (). A first contact layer () has at least one emitting surface () via which radiation emitted by an active layer () exits the LED. The emitting surfaces () are electrically and optically isolated from one another by surface implanted regions () in the first contact layer () which are irradiated with electric charge carriers. The areas of the layers located below the emitting surface () starting from the first contact layer () and proceeding as far as at least through the active layer () are electrically and optically isolated with respect to areas of the layers not located below the emitting surface () by means of first deep implanted regions () irradiated with electric charge carriers.

Surface-emitting semiconductor light-emitting diode

Techniques for the formation of silicon ingots and crystals using silicon feedstock of various grades are described. Common feature is adding a predetermined amount of germanium to the melt and performing a crystallization to incorporate germanium into the silicon lattice of respective crystalline silicon materials. Such incorporated germanium results in improvements of respective silicon material characteristics, mainly increased material strength. This leads to positive effects at applying such materials in solar cell manufacturing and at making modules from those solar cells. A silicon material with a germanium concentration in the range (50-200) ppmw demonstrates an increased material strength, where best practical ranges depend on the material quality generated.

Germanium-enriched silicon material for making solar cells

Techniques for controlling resistivity in the formation of a silicon ingot from compensated feedstock silicon material prepares a compensated, upgraded metallurgical silicon feedstock for being melted to form a silicon melt. The compensated, upgraded metallurgical silicon feedstock provides a predominantly p-type semiconductor for which the process assesses the concentrations of boron and phosphorus and adds a predetermined amount of aluminum or/and gallium. The process further melts the silicon feedstock together with a predetermined amount of aluminum or/and gallium to form a molten silicon solution from which to perform directional solidification and, by virtue of adding aluminum or/and gallium, maintains the homogeneity the resistivity of the silicon ingot throughout the silicon ingot. In the case of feedstock silicon leading to low resistivity in respective ingots, typically below 0.4 &#x3a9;cm, a balanced amount of phosphorus can be optionally added to aluminum or/and gallium. Adding phosphorus becomes mandatory at very low resistivity, typically close to 0.2 &#x3a9;cm and slightly below.

Method and system for controlling resistivity in ingots made of compensated feedstock silicon

Growing community of inventors

Berlin, Germany

Vera Abrosimova