Title :
Porous silicon gettering
Author :
Tsuo, Y.S. ; Menna, P. ; Pitts, J.R. ; Jantzen, K.R. ; Asher, S.E. ; Al-Jassim, M.M. ; Ciszek, T.F.
Author_Institution :
Nat. Renewable Energy Lab., Golden, CO, USA
Abstract :
We have studied a novel extrinsic gettering method that uses the large surface areas produced by a porous-silicon etch as gettering sites. The annealing step of the gettering used a high-flux solar furnace. We found that a high density of photons during annealing enhanced the impurity diffusion to the gettering sites. We used metallurgical-grade Si (MG-Si) prepared by directional solidification casting as the starting material. We propose to use porous-silicon-gettered MG-Si as a low-cost epitaxial substrate for polycrystalline silicon thin-film growth for solar cells
Keywords :
annealing; casting; crystal growth from melt; directional solidification; elemental semiconductors; getters; semiconductor epitaxial layers; semiconductor thin films; silicon; solar cells; substrates; Si; annealing; directional solidification casting; extrinsic gettering method; high photon density; high-flux solar furnace; impurity diffusion enhancement; large surface areas; low-cost epitaxial substrate; metallurgical-grade Si; polycrystalline silicon thin-film growth; porous silicon gettering; porous-silicon etch; solar cells; Annealing; Casting; Etching; Furnaces; Gettering; Impurities; Inorganic materials; Semiconductor thin films; Silicon; Substrates;
Conference_Titel :
Photovoltaic Specialists Conference, 1996., Conference Record of the Twenty Fifth IEEE
Conference_Location :
Washington, DC
Print_ISBN :
0-7803-3166-4
DOI :
10.1109/PVSC.1996.564043
