METHOD OF MANUFACTURING n-TYPE MULTICRYSTALLINE SILICON SOLAR CELLS

摘要

THE INVENTION PROVIDES A METHOD OF MANUFACTURING A HIT STRUCTURE FOR MULTICRYSTALLINE SILICON SUBSTRATE MADE OF AN N-TYPE MULTICRYSTALLINE SILICON SUBSTRATE. FIRST, THE N-TYPE MULTICRYSTALLINE SILICON SUBSTRATE IS SUBJECT TO A PHOSPHORUS DIFFUSION STEP USING A RELATIVELY HIGH TEMPERATURE. THE FRONT SIDE DIFFUSION LAYER IS THEN REMOVED. THROUGH THE PROCESS OF THE PHOSPHORUS DIFFUSION, IMPURITIES LIKE IRON INCLUDED DURING THE INGOT-CASTING ARE GETTERED AND THE BULK PROPERTY IS IMPROVED. THE PHOSPHORUS-DIFFUSED LAYER ALSO SERVES AS A BACK SURFACE FIELD TO RAISE THE VOLTAGE AND A BACK CONTACT WITH LOW RESISTIVITY. AS A NEXT STEP, A P-TYPE SILICON THIN FILM IS DEPOSITED AT THE FRONT SIDE OF THE SUBSTRATE. DUE TO THIS SPECIFIC SEQUENCE, HEATING THE P-TYPE SILICON THIN FILM AT HIGHER TEMPERATURES THAN ITS DEPOSITION TEMPERATURE CAN BE AVOIDED, AND SO THE QUALITY OF THE P-TYPE SILICON THIN FILM IS MAINTAINED.