Coated article with low-E coating having low visible transmission
View Patent ↗This invention relates to a coated article including a low-emissivity (low-E) coating. In certain example embodiments, the low-E coating is provided on a substrate (e.g., glass substrate) and includes at least first and second infrared (IR) reflecting layers (e.g., silver based layers) that are spaced apart by contact layers (e.g., NiCr based layers) and a dielectric layer of or including a material such as silicon nitride. In certain example embodiments, the coated article has a low visible transmission (e.g., no greater than 50%, more preferably no greater than about 40%, and most preferably no greater than about 39%).
1. A coated article including a coating supported by a glass substrate, the coating comprising:
first and second infrared (IR) reflecting layers comprising silver, the first IR reflecting layer being located closer to the glass substrate than is the second IR reflecting layer;
a first contact layer comprising NiCr located over and directly contacting the first IR reflecting layer comprising silver;
a dielectric layer comprising silicon nitride located over and directly contacting the first contact layer comprising NiCr;
a second contact layer comprising NiCr located over and directly contacting the layer comprising silicon nitride;
the second IR reflecting layer comprising silver located over and directly contacting the second contact layer comprising NiCr; and
wherein the second IR reflecting layer comprising silver is at least 10 angstroms (Å) thinner than the first IR reflecting layer comprising silver, and wherein the coated article has a visible transmission of no greater than 50%.
2. The coated article of claim 1 , wherein the first contact layer comprising NiCr is from about 15-30 Å thick.
3. The coated article of claim 1 , wherein said first contact layer comprising NiCr is from 8-22 Å thicker than the second contact layer comprising NiCr.
4. The coated article of claim 1 , wherein said first contact layer comprising NiCr is from 10-18 Å thicker than the second contact layer comprising NiCr.
5. The coated article of claim 1 , wherein the second contact layer comprising NiCr is from about 6-14 Å thick.
6. The coated article of claim 1 , wherein the second IR reflecting layer comprising silver is at least 20 angstroms (Å) thinner than the first IR reflecting layer comprising silver.
7. The coated article of claim 1 , wherein the second IR reflecting layer comprising silver is at least 40 angstroms (Å) thinner than the first IR reflecting layer comprising silver.
8. The coated article of claim 1 , wherein the dielectric layer comprising silicon nitride is amorphous.
9. The coated article of claim 1 , wherein the first contact layer comprising NiCr is substantially metallic or metallic and contains no more than about 5% (atomic %) oxygen.
10. The coated article of claim 1 , wherein the second contact layer comprising NiCr is substantially metallic or metallic and contains no more than about 5% (atomic %) oxygen.
11. The coated article of claim 1 , wherein said first and/or second contact layer further contains nitrogen.
12. The coated article of claim 1 , wherein said coated article has a visible transmission of from about 20-42% measured monolithically.
13. The coated article of claim 1 , wherein the coated article is thermally tempered.
14. The coated article of claim 1 , wherein the coated article is not heat treated.
15. The coated article of claim 1 , wherein the coated article is heat treated and has a glass side reflective ΔE* value of no greater than 4.6 due to the heat treatment.
16. The coated article of claim 1 , wherein the coated article is heat treated and has a glass side reflective ΔE* value of no greater than 3.6 due to the heat treatment.
17. The coated article of claim 1 , wherein the coated article is heat treated and has a glass side reflective ΔE* value of from 3.0 to 4.6 due to the heat treatment.
18. The coated article of claim 1 , wherein the coating further comprises another dielectric layer comprising silicon nitride located over at least the second IR reflecting layer.
19. The coated article of claim 18 , wherein said another dielectric layer comprising silicon nitride is from 150-290 Å thick.
20. The coated article of claim 18 , wherein the coating further comprises an overcoat comprising zirconium oxide located over and directly contacting the another dielectric layer comprising silicon nitride.
21. The coated article of claim 1 , wherein the coating further comprising a bottom layer comprising silicon nitride located on and directly contacting the glass substrate, and another contact layer comprising NiCr located between and directly contacting the bottom layer comprising silicon nitride and the first IR reflecting layer comprising silver.
22. The coated article of claim 1 , wherein the first IR reflecting layer comprising silver is from 110-145 Å thick, and the second IR reflecting layer comprising silver is from 60-95 Å thick.
23. The coated article of claim 1 , wherein the coating has a sheet resistance (R s ) of less than or equal to 4.0 ohms/square.
24. A laminated window comprising the coated article of claim 1 laminated to another substrate.
25. A coated article including a coating supported by a glass substrate, comprising:
first and second infrared (IR) reflecting layers, the first IR reflecting layer being located closer to the glass substrate than is the second IR reflecting layer;
a first substantially metallic contact layer comprising NiCr located over and directly contacting the first IR reflecting layer, the first substantially metallic contact layer comprising NiCr being from about 15-30 Å thick;
a dielectric layer comprising silicon nitride located over and directly contacting the first contact layer comprising NiCr;
a second substantially metallic contact layer comprising NiCr located over and directly contacting the layer comprising silicon nitride;
the second IR reflecting layer located over and directly contacting the second contact layer comprising NiCr; and
wherein the second IR reflecting layer comprising silver is at least 10 angstroms (Å) thinner than the first IR reflecting layer comprising silver, and wherein the coated article has a visible transmission of no greater than 50%.
26. The coated article of claim 25 , wherein said first contact layer comprising NiCr is from 8-22 Å thicker than the second contact layer comprising NiCr.
27. The coated article of claim 25 , wherein the second IR reflecting layer comprising silver is at least 40 angstroms (Å) thinner than the first IR reflecting layer comprising silver.
28. The coated article of claim 25 , wherein said coated article has a visible transmission of from about 20-42% measured monolithically.
29. The coated article of claim 25 , wherein the coated article is heat treated and has a glass side reflective ΔE* value of no greater than 4.6 due to the heat treatment.
30. A method of making a coated article including a coating supported by a glass substrate, the method comprising:
sputter-depositing first and second infrared (IR) reflecting layers comprising silver, the first IR reflecting layer being located closer to the glass substrate than is the second IR reflecting layer;
sputter-depositing a first contact layer comprising NiCr located over and directly contacting the first IR reflecting layer comprising silver;
sputter-depositing a dielectric layer comprising silicon nitride located over and directly contacting the first contact layer comprising NiCr;
sputter-depositing a second contact layer comprising NiCr located over and directly contacting the layer comprising silicon nitride, the second IR reflecting layer comprising silver located over and directly contacting the second contact layer comprising NiCr; and
wherein the second IR reflecting layer comprising silver is at least 10 angstroms (Å) thinner than the first IR reflecting layer comprising silver, and wherein the coated article has a visible transmission of no greater than 50% measured monolithically.