Calisolar Inc.

Silicor Materials Inc.

Jean Patrice Rakotoniaina

Kamel Ounadjela

Fritz Kirscht

Dieter Linke

Martin Kaes

Bill Phan

Alain Paul Blosse

Matthias Heuer

Vera Abrosimova

Anis Jouini

Omar Sidelkheir

Renhua Zhang

John Gorman

A polarization resistant solar cell using an oxygen-rich interface layer is provided. The oxygen-rich interface layer may be comprised of SiON, which may have a graded profile that varies between oxygen-rich proximate to the solar cell to nitrogen-rich distal to the solar cell. A silicon oxide passivation layer may be interposed between the solar cell and the SiONgraded dielectric layer. The graded SiONdielectric layer may be replaced with a non-graded SiONdielectric layer and a SiN AR coating.

Polarization resistant solar cell design using an oxygen-rich interface layer

Techniques are here disclosed for a solar cell pre-processing method and system for annealing and gettering a solar cell semiconductor wafer having an undesirably high dispersion of transition metals, impurities and other defects. The process forms a surface contaminant layer on the solar cell semiconductor (e.g., silicon) wafer. A surface of the semiconductor wafer receives and holds impurities, as does the surface contaminant layer. The lower-quality semiconductor wafer includes dispersed defects that in an annealing process getter from the semiconductor bulk to form impurity cluster toward the surface contaminant layer. The impurity clusters form within the surface contaminant layer while increasing the purity level in wafer regions from which the dispersed defects gettered. Cooling follows annealing for retaining the impurity clusters and, thereby, maintaining the increased purity level of the semiconductor wafer in regions from which the impurities gettered. Multicrystalline semiconductor wafers having grain boundaries with impurities may also undergo the annealing and gettering of dispersed defects to the grain boundaries, further increasing the semiconductor substrate purity levels.

Semiconductor wafer pre-process annealing and gettering method and system for solar cell formation

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

Growing community of inventors

Berlin, Germany

Jean Patrice Rakotoniaina