화학공학소재연구정보센터
Applied Surface Science, Vol.257, No.5, 1612-1615, 2010
Solar cell fabrication using edge-defined film-fed growth (EFG) silicon wafers
The insufficient supply of polysilicon is limiting the growth of the segment of the photovoltaic industry using silicon materials. Because it is grown directly in the form of ribbon from a silicon melt, edge-defined film-fed growth (EFG) silicon ribbon is a promising alternative for cutting down wafer costs by reducing the polysilicon consumption and eliminating kerf loss. In this paper, we will discuss the various properties that can be achieved with for low cost and high-efficiency EFG silicon ribbon solar cell fabrication. Boron-doped p-type EFG ribbon silicon wafers with resistivities of 2-4 Omega cm and a size of 125mm x 125mm were used. The major fabrication steps we studied were mixed acid (HF, HNO3, DI water) texturing, phosphorus diffusion with POCl3, thermal oxide growth for surface passivation, laser process for edge isolation, and PECVD of SiNx:H for surface passivation and antireflection coating. By optimizing the processing steps, we achieved a conversion efficiency, open circuit voltage, short circuit current, and fill factor as high as 14.5%, 584 mV, 32.1 mA/cm(2), and 77%, respectively. (c) 2010 Elsevier B.V. All rights reserved.