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Surface passivation of phosphorus‐diffused n + ‐type emitters by plasma‐assisted atomic‐layer deposited Al 2 O 3
Author(s) -
Hoex B.,
van de Sanden M. C. M.,
Schmidt J.,
Brendel R.,
Kessels W. M. M.
Publication year - 2012
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201105445
Subject(s) - passivation , doping , common emitter , atomic layer deposition , layer (electronics) , materials science , analytical chemistry (journal) , silicon , deposition (geology) , optoelectronics , nanotechnology , chemistry , paleontology , sediment , biology , chromatography
In recent years Al 2 O 3 has received tremendous interest in the photovoltaic community for the application as surface passivation layer for crystalline silicon. Especially p‐type c‐Si surfaces are very effectively passivated by Al 2 O 3 , including p‐type emitters, due to the high fixed negative charge in the Al 2 O 3 film. In this Letter we show that Al 2 O 3 prepared by plasma‐assisted atomic layer deposition (ALD) can actually provide a good level of surface passivation for highly doped n‐type emitters in the range of 10–100 Ω/sq with implied‐ V oc values up to 680 mV. For n‐type emitters in the range of 100–200 Ω/sq the implied‐ V oc drops to a value of 600 mV for a 200 Ω/sq emitter, indicating a decreased level of surface passivation. For even lighter doped n‐type surfaces the passivation quality increases again to implied‐ V oc values well above 700 mV. Hence, the results presented here indicate that within a certain doping range, highly doped n‐ and p‐type surfaces can be passivated simultaneously by Al 2 O 3 . (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)