Method of making float glass with transparent conductive oxide (TCO) film integrally formed on tin bath side of glass and corresponding product
View Patent ↗A method of making float glass is provided that results in a transparent conductive oxide (TCO) films being integrally formed with the float glass at the tin side thereof. In particular, a donor(s) such as antimony and/or an oxide thereof is added to the glass batch during the process of manufacture. The donor diffuses into the tin oxide inclusive layer adjacent the tin bath during the “float” manufacturing process, thereby increasing the number of electrons in the tin oxide inclusive layer so as to form a TCO film at the tin side of the glass.
1. A method of making float glass having a thin conductive electrode layer at a surface thereof, the method comprising:
providing a glass batch including soda, lime, silica and antimony;
causing molten glass from the batch to be provided on a top surface of a tin bath, causing antimony in the glass batch to diffuse downward in the molten glass toward the tin bath and into a tin oxide inclusive film at a surface where the molten glass meets the tin bath, the antimony changing electrical properties of the tin oxide inclusive film to make it more conductive, thereby causing a transparent conductive tin oxide inclusive film that is doped with antimony to be formed at the glass surface adjacent the tin bath forming a thin transparent conductive electrode layer as part of the glass; and
wherein the antimony increases the number of electrons in the tin oxide inclusive film formed at the glass surface so as to result in the formation of a transparent conductive tin oxide inclusive film at the glass surface that was adjacent the tin bath.
2. The method of claim 1 , wherein the antimony comprises antimony oxide.
3. The method of claim 1 , wherein the antimony is added to the glass batch in the form of one or more of Sb 2 O 3 , NaSbO 3 and Sb(Sb 2 O 5 ).
4. The method of claim 1 , wherein the antimony and/or oxide thereof makes up from about 1-5% of the glass batch.
5. The method of claim 1 , wherein the resulting glass is provided in a solar cell so that the transparent conductive electrode of the glass functions as an electrode of the solar cell.
6. The method of claim 5 , wherein the solar cell comprises another electrode, and wherein at least a photoelectric film is provided between at least the another electrode and the conductive oxide film.
7. The method of claim 1 , wherein the glass comprises:
Ingredient
wt. %
SiO 2
67-75%
Na 2 O
10-20%
CaO
5-15 %
total iron (expressed as Fe 2 O 3 )
0.001 to 0.06%
cerium oxide
0 to 0.07%
antimony oxide
0.01 to 10%.
8. The method of claim 1 , wherein the glass has visible transmission of at least 90%, a transmissive a* color value of −1.0 to +1.0 and a transmissive b* color value of from 0 to +1.5.
9. The method of claim 1 , wherein the glass has a redox value (FeO/Fe 2 O 3 ) no greater than 0.06.
10. The method of claim 1 , wherein the glass substrate has a redox value (FeO/Fe 2 O 3 ) no greater than 0.04.
11. The method of claim 1 , wherein the glass is substantially free of two or more of erbium oxide, nickel oxide, cobalt oxide, neodymium oxide, chromium oxide, cerium oxide and selenium.
12. The method of claim 1 , wherein the glass includes at least twice as much antimony oxide as total iron oxide, by weight.