Formulations And Methods For Surface Cleaning And Passivation of CdTe Substrates
AssigneeFirst Solar, Inc.
InventorsScott Christensen, Scott Jewhurst, Minh Huu Le, Haifan Liang, Hao Lin, Wei Liu, Minh Anh Nguyen, Zhi Wen Sun, Gang Xiong
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Abstract
Methods and compositions for the surface cleaning and passivation of CdTe substrates usable in solar cells are disclosed. In some embodiments amine-containing chelators are used and in other embodiments phosphorus-containing chelators are used.
Claims19
A surface cleaning bath comprising:
- a first chelating agent component selected from an amine, an amine derivative, or mixtures thereof;
- and
- optionally, a second chelating agent having a poly-hydroxy-carboxylic acid.
A surface passivation bath comprising:
- a source of sulfur;
- a zinc salt;
- and
- one or more bases.
A method for surface cleaning and passivating a II-VI semiconductor substrate, the method comprising:
- cleaning a II-VI semiconductor substrate with a cleaning solution comprising a surface cleaning bath according to claim 20;
- and
- passivating the surface-cleaned II-VI semiconductor substrate with a passivation solution comprising a source of sulfur, zinc salts, and one or more bases.
A surface cleaning and passivation bath comprising a phosphorous-containing chelating agent component, the phosphorous-containing chelating agent component consisting essentially of a phosphorous-containing organic compound at a concentration ranging from about 0.02 M to about 1 M.
Dependencies are inferred from the claim text.