Oxygen and lattice distortions in multicrystalline silicon

• Published in: Solar energy materials and solar cells 2002-04, Vol.72 (1), p.403-416
• Main Authors: Möller, H.J., Funke, C., Lawerenz, A., Riedel, S., Werner, M.
• Format: Article
• Language: English
• Subjects: Applied sciences; Crystal growth; Crystal impurities; Crystal lattices; Crystalline materials; Dislocations; Dislocations (crystals); Energy; Exact sciences and technology; Internal stresses; Interstitial oxygen; Light polarization; Natural energy; Oxygen; Oxygen-precipitation; Photovoltaic conversion; Precipitation (chemical); Silicon solar cells; Silicon wafers; Solar cells. Photoelectrochemical cells; Solar energy; Solar-silicon
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/S0927-0248(01)00188-X

Oxygen is one of the main impurities in multicrystalline silicon for photovoltaic applications. Precipitation of oxygen occurs during crystal growth and solar cell processing. It is shown that dislocations enhance the oxygen precipitation. Depending on the thermal conditions and the initial oxygen content various types of SiO 2+precipitates and oxygen related defects are observed and investigated by fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy. The large area distribution of oxygen decorated dislocations is studied by scanning infrared microscopy (SIRM). Both inhomogeneous distributions of dislocations and oxygen precipitates occur and can lead to internal stresses. The internal stresses of multicrystalline-silicon wafers are investigated by an optical method using polarized infrared light. The results are compared with the dislocation microstructure and the oxygen distribution in wafers produced by different growth techniques.