Polymerized solutions for depositing optical oxide coatings
First Claim
1. A substrate having an oxide coating thereon which has a predetermined index of refraction between about 1.4 and about 2.4 made by(A) preparing a clear solution which comprises:
- (1) alkoxide having the general formula M(OR)n where M is selected from the group consisting of 0 to 100% Ti, 0 to 25% Si, 0 to 100% Ta, and up to 15% of a metal ion which forms an alkoxide, R is alkyl from C1 to C6, and n is the valence of M;
(2) about 1.7 to about 4 moles of water per mole of alkoxide;
(3) sufficient alcohol to give a solids content of about 0.1 to about 15% and(4) a sufficient amount of a suitable acid to prevent cloudiness;
(B) applying said clear solution to said substrate; and
(C) heating said substrate to about 300°
to about 600°
C.
1 Assignment
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Accused Products
Abstract
A clear solution is prepared by reacting metal alkoxide with a mixture of critical amounts of water and/or acid in an alcohol diluted medium. Alkoxides may be Ti(OR)4 or Ta(OR)5, or another metal alkoxide such as Si(OR)4 in admixture with these alkoxides. Acids may be HCl or HNO3. Quarter wave inorganic optical coatings are deposited by applying the alkoxide solution to a substrate then heating the coating at over 350° C. The coatings reduce reflectivity on silicon solar cells. The index of refraction of the coating can be varied by several techniques, including altering the proportion of titanium and silicon in the coating firing temperature, firing atmosphere. Thicknesses of the coating can be controlled by varying the rpm in spin application, withdrawal rate in dipping application, by concentration of the solution, by the type of solvent or the degree of polymerization of the titanium complexes.
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Citations
12 Claims
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1. A substrate having an oxide coating thereon which has a predetermined index of refraction between about 1.4 and about 2.4 made by
(A) preparing a clear solution which comprises: -
(1) alkoxide having the general formula M(OR)n where M is selected from the group consisting of 0 to 100% Ti, 0 to 25% Si, 0 to 100% Ta, and up to 15% of a metal ion which forms an alkoxide, R is alkyl from C1 to C6, and n is the valence of M; (2) about 1.7 to about 4 moles of water per mole of alkoxide; (3) sufficient alcohol to give a solids content of about 0.1 to about 15% and (4) a sufficient amount of a suitable acid to prevent cloudiness; (B) applying said clear solution to said substrate; and (C) heating said substrate to about 300°
to about 600°
C. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification