Silver composition for micro-deposition direct writing silver conductor lines on photovoltaic wafers
View Patent ↗Embodiments of the invention relate to a silicon semiconductor device, and a conductive thick film composition for use in a solar cell device.
1. A composition comprising:
(a) one or more conductive materials comprising silver;
(b) one or more inorganic binders; and
(c) organic vehicle,
wherein (i) 1 to 15% of the conductive components are submicron particles; (ii) wherein 85 to 99% of the conductive components have a d50 of 1.5 to 10 microns; and wherein the conductive components (i) and (ii) have a bimodal size distribution.
2. The composition of claim 1 , wherein the submicron particles have a d50 of 0.1 to 0.6 microns.
3. The composition of claim 1 further comprising one or more additives.
4. The composition of claim 3 , wherein the one or more additives comprise components selected from the group consisting of:
(a) a metal wherein said metal is selected from Zn, Pb, Bi, Gd, Ce, Zr, Ti, Mn, Sn, Ru, Co, Fe, Cu, and Cr;
(b) a metal oxide of one or more of the metals selected from Zn, Pb, Bi, Gd, Ce, Zr, Ti, Mn, Sn, Ru, Co, Fe, Cu and Cr;
(c) any compounds that can generate the metal oxides of (b) upon firing; and
(d) mixtures thereof.
5. The composition of claim 4 , wherein the one or more inorganic additives comprises ZnO.
6. The composition of claim 1 , wherein the submicron particles further comprise ZnO and an inorganic binder.
7. The composition of claim 1 , wherein the one or more inorganic binders comprise glass frit.
8. The composition of claim 1 , wherein the inorganic components are 70 to 95 wt % of the total composition.