POLYCRYSTALLINE SILICON THIN FILMS SOLAR CELLS PREPARED BY PECVDSPC

BUITRAGO R.H., RISSO G.A., CUTRERA M., BATTIONI M., DE BERNARDEZ L., SCHMIDT J.A., ARCE R.D.

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

Año: 2007

0360-3199

Among the most promising technological alternatives for the development of photovoltaic modules and cells of a low cost, good energetic conversion and feasibility for mass production, polycrystalline silicon thin films solar cells deposited directly on a transparent substrate, are currently being considered the best. We have developed in our laboratory a PECVD reactor capable of producing the deposition of amorphous hydrogenated silicon at rates of above 2 nm/seg, allowing a significant production per line on the plant. Discharge gas is silane, to which diborane or phosphine is added so as to form the cell. Basically, work is done on a structure of cell type TCO/n+/p-/p+/M, 2 microns total thickness. Schott AF-37 glass is used as substrate, for their ability to withstand temperatures of up to 800 ¢XC. The amorphous cell is subsequently annealed at gradual temperatures of 100 ¢XC to achieve dehydrogenation up to 650-700 ¢XC for 12 hours until their complete crystallization is achieved. Our results show a complete crystallization of silicon with a grain size of less than a micron, with a dehydrogenation process at 500 ¢XC, leaving a remainder of less than 1% in hydrogen as monohydrate. The parameters of cell estimated from the IV curve yield low values, FF < 0,55, Icc <200 ƒÝA and Voc < 420 mV. The high series resistance is due to grain size and defect density, which will be attempted to be improved by posthydrogenation and rapid thermal annealing methods at high temperatures (RTA). The high series resistance is due to grain size and defect density, which will be attempted to be improved by posthydrogenation and rapid thermal annealing methods at high temperatures (RTA). The high series resistance is due to grain size and defect density, which will be attempted to be improved by posthydrogenation and rapid thermal annealing methods at high temperatures (RTA). ƒÝA and Voc < 420 mV. The high series resistance is due to grain size and defect density, which will be attempted to be improved by posthydrogenation and rapid thermal annealing methods at high temperatures (RTA).