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HIGH EFFICIENCY THIN FILM SOLAR CELLS UPGRADED METALLURGICAL GRADE SILICON SUBSTRATES.

Objective

EVALUATION OF THE POTENTIAL OF EPITAXIAL SOLAR CELLS ON UPGRADED METALLURGICAL GRADE SILICON SUBSTRATES FOR HIGH EFFICIENCY LOW COST PHOTOVALTICS.

ABOUT 10 KG SILICON INGOTS HAVE BEEN GROWN BY USING THE BRIDGMAN-STOCKBARGER TECHNIQUE SET UP BY PRAGMA AND ALREADY USED FOR PILOT PRODUCTION PURPOSES OF OFF-GRADE POLYCRYSTALLINE SILICON INGOTS.

THE INGOTS HAVE BEEN GROWN BY DELIBERATELY DOPING EG SILICON WITH DIFFERENT AMOUNT OF DOPANTS AND FULLY CHARACTERIZED FOR PV PROPERTIES, BY MANUFACTURING AND TESTING 10X10 CM2, DIFFUSE JUNCTION CELLS.

ON THIS MATERIAL SYSTEMATIC OPTICAL AND ELECTRICAL CHARACTERIZATION WILL BE CARRIED OUT IN ORDER TO UNDERSTAND THE ROLE AND THE MAXIMUM AMOUNT OF THE IMPURITIES COMPATIBLE WITH GOOD PV PERFORMANCES.
BY THE SAME DIRECTIONAL SOLIDIFICATION TECHNIQUE MG SILICON INGOTS HAVE BEEN ONCE AND TWICE RECRYSTALLIZED. THE MG SILICON WAS DELIVERED BY SAMIM ABRASIVI OF ENI GROUP COMPANY IN PARTNERSHIP WITH PRAGMA FOR UPGRADED MG SILICON DEVELOPMENT. THE MG FEEDSTOCK WAS BLENDED WITH 50% OF EG SILICON AND FROM THE INGOTS OF FIRST CRYSTALLIZATION WAS OBTAINED TWO INGOTS OF SECOND CRYSTALLIZATION. A PRELIMINARY EVALUATION OF THE PHOTOVOLTAIC PROPERTIES WAS CARRIED OUT IN PRAGMA BY PROCESSING A STOCK OF ABOUT 60 WAFERS CARRING FROM THESE INGOTS.
THE MEAN PV EFFICIENCY VALUE REACHED WAS IN EXCESS 5.5% FOR BOTH THE INGOTS. ON WAFERS CARRING FROM ONE OF THESE INGOTS EPI-LAYER SOLAR CELLS WERE REALIZED BY IMEC GROUP REACHING A TOP EFFICIENCY OF ABOUT 12%.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

Italsolar SpA
Address
Via A D'andrea 6
00048 Nettuno
Italy