DocumentCode :
1561011
Title :
N-type multicrystalline silicon wafers for solar cells
Author :
Martinuzzi, Santo ; Palais, Olivier ; Pasquinelli, M. ; Barakel, D. ; Ferrazza, Francesca
Author_Institution :
Fac. of Sci., Paul Cezanne-Aix-MarseilleIII Univ., France
fYear :
2005
Firstpage :
919
Lastpage :
922
Abstract :
In n-type silicon the capture cross sections of metallic impurities, are neatly smaller than in p-type. So, lifetime and also diffusion length of minority carriers should be neatly higher. This is of a paramount interest for multicrystalline silicon wafers, in which the impurity-defects interaction governs the recombination strength of minority carriers. In 1.2 Ωcm wafer, lifetime is found around 200 μs and diffusion lengths around 220 μm, These values increase strongly after gettering treatments like phosphorus diffusion or AI-Si alloying. Scan maps reveal that extended defects are poorly active, even when the density of dislocation is higher than 105 cm-2. High quality abrupt p+n junctions are obtained by Al-Si alloying and annealing at 850 or 900 °C, which could be used for rear junction cells.
Keywords :
aluminium alloys; annealing; carrier lifetime; diffusion; dislocation density; electron-hole recombination; elemental semiconductors; extended defects; impurities; impurity-defect interactions; minority carriers; p-n junctions; phosphorus; silicon; silicon alloys; solar cells; 850 to 900 degC; Al-Si; Si:P; annealing; diffusion length; dislocation density; extended defects; impurity-defects interaction; metallic impurities; minority carrier lifetime; n-type multicrystalline silicon wafers; phosphorus diffusion; rear junction cells; recombination strength; solar cells; Alloying; Aluminum; Boron; Charge carrier processes; Gettering; Impurities; Photovoltaic cells; Photovoltaic systems; Silicon; Solar power generation;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Photovoltaic Specialists Conference, 2005. Conference Record of the Thirty-first IEEE
ISSN :
0160-8371
Print_ISBN :
0-7803-8707-4
Type :
conf
DOI :
10.1109/PVSC.2005.1488281
Filename :
1488281
Link To Document :
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