The high cost of crystalline silicon solar cells has been considered as one of the major obstacles to their terrestrial applications. Spin on doping (SOD) is presented as a useful process for the manufacturing of low cost solar cells. Phosphorus (P509) was used as an n-type emitters of solar cells. N-type emitters were formed on p-type EFG ribbon Si wafers by using a SOD at different spin speed (1,000∼4,000 rpm), diffusion temperatures (800℃∼950℃), and diffusion time (5∼30 min) in N2+O2 atmosphere. With optimum condition, we were able to achieve cell efficiency of 14.1%.

Ribbon silicon solar cells have been investigated because they can be produced with a lower material cost. However, it is very difficult to get good texturing with a conventional acid solution. To achieve high efficiency should be minimized for the reflectance properties. In this paper, acid vapor texturing and anti-reflection coating of SiNx was applied for EFG Ribbon Si Wafer. P-type ribbon silicon wafer had a thickness of 200 um and a resistivity of 3 n-㎝. Ribbon silicon wafers were exposed in an acid vapor. Acid vapor texturing was made by reaction between the silicon and the mixed solution of HF: HNO3. After acid vapor texturing process, nanostructure of less than size of 1 um was formed and surface reflectance of 6.44% was achieved. Reflectance was decreased to 2.37% with anti-reflection coating of SiNx.