A PHOTOCHEMCIAL METHOD FOR THE PRODUCTION OF SEMICONDUCTOR GRADE SILICON FOR USE IN ENERGY CONVERSION DEVICES

THE LARGE SCALE USE OF PHOTOVOLTAIC-GENERATED ELECTRICITY HINGES CRUCIALLY ON THE COST OF ITS PRODUCTION. THE HIGH COST OF PRODUCTION OF THE SINGLE CRYSTAL SILICON TECHNOLOGY HAS PROHIBITED ITS TERRESTIAL EXPLOITATION. IN SPITE OF IMPROVEMENTS HERE AND THE DEVELOPMENT OF POLYCRYSTALLINE SILICON, THE MARKET PENETRATION DEMANDS FURTHER DRASTIC COST REDUCTIONS. THIN FILM AMORPHOUS SILICON IS EMERGING AS THE NEXT GENERATION SOLAR CELL MATERIAL, WITH PROMISE ALREADY OF MUCH LOWER COST OF PRODUCTION. THE PROGRESS IN AMORPHOUS SILICON TECHNOLOGY HAS BEEN RAPID ENOUGH THAT IT IS NOW AT THE MANUFACTURING STAGE. THE COMMERCIAL METHOD FOR THE PRODUCTION OF AMORPHOUS SILICON IS THE SO-CALLED GLOW DISCHARGE METHOD, USING SILANE AS THE THE FEED-STOCK. FURTHER COST REDUCTION IN THETECHNOLOGY MANDATES AN INQUIRY INTO OTHER METHODS TO PREPARE AMORPHOUS SILICON. PHOTO-CHEMICAL METHODS ARE SHOWING GREAT PROMISE, WITH EXPECTATIONS OF A BETTER QUALITY AMORPHOUS SILICON AS GENTLER CONDITIONS PREVAIL DURING DEPOSITION. THIS PROPOSAL IS A PHOTOCHEMICAL METHOD FOR THE PRODUCTION OF AMORPHOUS SILICON. BUT IT DIFFERS VERY MUCH FROM PREVIOUS APPROACHES IN THE WAY THE REACTANTS (SILANES) ARE READIED FOR PHOTOLYSIS. IT AVOIDS SOME PREVIOUSLY ENCOUNTERED PROBLEMS, LIKE WINDOW CLOUDING. IT SHOWS PROMISE OF ADAPTABILITY TO PREPARE POLYCRYSTALLINE SILICON ALSO.