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Thermal stability of the Al 2 O 3 passivation on p‐type silicon surfaces for solar cell applications
Author(s) -
Benick Jan,
Richter Armin,
Hermle Martin,
Glunz Stefan W.
Publication year - 2009
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.200903209
Subject(s) - passivation , silicon , materials science , thermal stability , annealing (glass) , solar cell , boron , doping , saturation current , common emitter , open circuit voltage , analytical chemistry (journal) , optoelectronics , nanotechnology , chemical engineering , metallurgy , chemistry , voltage , layer (electronics) , electrical engineering , organic chemistry , chromatography , engineering
Al 2 O 3 has been shown to provide an outstanding passivation quality on p‐type surfaces after annealing at moderate temperatures (∼425 °C). However, most industrial silicon solar cells are based on printing technologies for metallization, including a high temperature firing step for the contact formation. To investigate the thermal stability of the Al 2 O 3 passivation, symmetrical p and p + np + lifetime samples were coated with Al 2 O 3 and exposed to typical firing processes at temperatures between 700 °C and 850 °C. Up to a firing temperature of 825 °C the Al 2 O 3 passivation is shown to be stable on highly boron‐doped surfaces. An emitter saturation current density of ∼60 fA/cm 2 could be measured for the p + np + samples, allowing a maximum open circuit voltage ( V oc ) >695 mV. The firing stability of the Al 2 O 3 is an important step for the realization of an industrial n‐type silicon solar cell. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)