Fabrication of large-area boron backfield silicon solar cells

Abstract

Both boron back field and aluminum back field can be used in the production of solar cells. The backfield could make sure solar cells have higher open circle voltage and higher conversion efficiency. The aluminum has the advantage of low cost and simpleness, so it is suitable for commercial production. But the aluminum backfield structure is not suit for new structure cells. Up to now, the boron backfield is commonly used in the fabrication of space solar cells. This paper will introduce how to realize boron backfield structure in commercial large-area cells production, and combine the boron backfield with screening, sintering and other technics. At last, we obtained solar cells with the open-circuit voltage of 600mV with boron diffusion, using p-type silicon wafer with resistance of 2 Ω · cm, with the size of 125mm × 125mm.