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Impact of phosphorus gettering parameters and initial iron level on silicon solar cell properties
Author(s) -
Vähänissi Ville,
Haarahiltunen Antti,
Talvitie Heli,
YliKoski Marko,
Savin Hele
Publication year - 2013
Publication title -
progress in photovoltaics: research and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.286
H-Index - 131
eISSN - 1099-159X
pISSN - 1062-7995
DOI - 10.1002/pip.2215
Subject(s) - getter , common emitter , phosphorus , silicon , materials science , impurity , carrier lifetime , open circuit voltage , diffusion , contamination , analytical chemistry (journal) , optoelectronics , chemical engineering , chemistry , metallurgy , voltage , environmental chemistry , electrical engineering , thermodynamics , physics , ecology , organic chemistry , biology , engineering
We have studied experimentally the effect of different initial iron contamination levels on the electrical device properties of p‐type Czochralski‐silicon solar cells. By systematically varying phosphorus diffusion gettering (PDG) parameters, we demonstrate a strong correlation between the open‐circuit voltage ( V oc ) and the gettering efficiency. Similar correlation is also obtained for the short‐circuit current ( J sc ), but phosphorus dependency somewhat complicates the interpretation: the higher the phosphorus content not only the better the gettering efficiency but also the stronger the emitter recombination. With initial bulk iron concentration as high as 2 × 10 14 cm −3 , conversion efficiencies comparable with non‐contaminated cells were obtained, which demonstrates the enormous potential of PDG. The results also clearly reveal the importance of well‐designed PDG: to achieve best results, the gettering parameters used for high purity silicon should be chosen differently as compared with for a material with high impurity content. Finally we discuss the possibility of achieving efficient gettering without deteriorating the emitter performance by combining a selective emitter with a PDG treatment. Copyright © 2012 John Wiley & Sons, Ltd.