Investigation of Defects in the Edge Region of Multicrystalline Solar Silicon Ingots

M. Rossberg; M. Naumann; K. Irmscher; U. Juda; A. Lüdge; Michael Ghosh; Armin Müller

doi:10.4028/www.scientific.net/SSP.108-109.531

Paper Titles

Crack Detection and Analyses Using Resonance Ultrasonic Vibrations in Full-Size Crystalline Silicon Wafers
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Multicrystalline Silicon from Different Types of Bridgman Furnaces: Ingot and Cell Properties
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Behaviour of Natural and Implanted Iron during Annealing of Multicrystalline Silicon Wafers
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Improved P-Type or Raw N-Type Multicrystalline Silicon Wafers for Solar Cells
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Investigation of Defects in the Edge Region of Multicrystalline Solar Silicon Ingots
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Electrical and Optical Characterization of Thin Semiconductor Layers for Advanced ULSI Devices
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DLTS Study on Deep Levels Formed in Plasma Hydrogenated and Subsequently Annealed Silicon
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Defect Behaviour in Deuterated and Non-Deuterated n-Type Si
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Thermal Stability of Ti/Mo Schottky Contacts on p-Si and Defects Introduced in p-Si during Electron Beam Deposition of Ti/Mo
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HomeSolid State PhenomenaSolid State Phenomena Vols. 108-109Investigation of Defects in the Edge Region of...

Investigation of Defects in the Edge Region of Multicrystalline Solar Silicon Ingots

Abstract:

The structural and electrical properties of as grown multicrystalline (mc) solar silicon have been characterized with special emphasis on the ingot's edge regions. For this purpose a vertical cross section of an mc-Si Bridgman ingot was investigated by Fourier transform infrared spectroscopy (FTIR), laser scattering tomography (LST), lateral photovoltage scanning (LPS), infrared microscopy and microwave detected photoconductivity decay (&PCD). Images of the distribution of dislocations, grain boundaries, precipitates, impurities (O, N, C) and the minority charge carrier lifetime were obtained, partly differentiating the defects by their electrical activity. In particular the LPS method displays dopant striations indicating the shape of the phase boundary. Deviations of the phase boundary from a slightly convex shape in the middle of the ingot to a concave one in the vicinity of the side walls could be observed. The existence of an horizontal temperature gradient deduced from this shape is the reason for convection in the melt. The influence on the concentration profiles of interstitial oxygen and the correlation with the minority charge carrier lifetime are discussed.