Abstract:
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 Ωcm, 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 Ωcm and slightly below.
Abstract:
Die Erfindung betrifft eine oberflächenemittierende Halbleiter-Leuchtdiode (LED), die dadurch gekennzeichnet ist, dass zwischen einem Substrat (2) und einer ersten Barriereschicht (5) eine Reflektorschicht (4) des ersten Leitfähigkeitstyps vorhanden ist, dass die erste Kontaktschicht (9) mindestens eine emittierende Oberfläche (13) aufweist, über die von einer aktiven Schicht (6) emittierte Strahlung aus der LED austritt und die emittierenden Oberflächen (13) gegeneinander durch mit elektrischen Ladungsträgern bestrahlten, oberflächenimplantierten Bereichen (11) in der ersten Kontaktschicht (9) elektrisch und optisch voneinander isoliert sind und dass die unter der emittierenden Oberfläche (13) befindlichen Bereiche der Schichten, ausgehend von der ersten Kontaktschicht (9) bis mindestens durch die aktive Schicht (6) hindurch, durch mit elektrischen Ladungsträgern bestrahlten, ersten tiefenimplantierten Bereichen (12.1) elektrisch und optisch gegen nicht unter der emittierenden Oberfläche (13) befindliche Bereiche der Schichten isoliert sind.
Abstract:
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.
Abstract:
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.
Abstract:
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.