Devices containing silver compositions deposited by micro-deposition direct writing silver conductor lines
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 method for making a semiconductor device comprising the steps of:
(a) providing a semiconductor substrate, one or more insulating films, and the thick film composition;
(b) applying the insulating film to the semiconductor substrate,
(c) applying the thick film composition to the insulating film on the semiconductor substrate, and
(d) firing the semiconductor, insulating film and thick film composition, wherein the thick film composition comprises:
(i) one or more conductive materials;
(ii) one or more inorganic binders; and
(iii) organic vehicle,
wherein 1 to 15 wt % of the inorganic components are submicron particles, characterised in that 1 to 15 wt % of the conductive materials have a d50 of 0.2 to 0.6 microns, and
85 to 99 wt % of the conductive materials have a d50 of 1.5 to 10 microns.
2. A semiconductor device comprising an electrode, wherein the electrode, prior to firing, comprises a composition comprising:
(a) one or more conductive materials;
(b) one or more inorganic binders; and
(c) organic vehicle,
wherein 1 to 15 wt % of the inorganic components are submicron particles, characterised in that 1 to 15 wt % of the conductive materials have a d50 of 0.2 to 0.6 microns,
and 85 to 99 wt % of the conductive materials have a d50 of 1.5 to 10 microns.
3. The device of claim 2 , wherein the one or more conductive materials comprise silver.
4. The device of claim 3 , wherein the submicron particles comprise silver.
5. The device of claim 4 , wherein the submicron particles further comprise ZnO and an inorganic binder.
6. The device of claim 2 , wherein the inorganic components have a bimodal size distribution.
7. The device of claim 2 , wherein the thick film composition further comprises one or more additives.
8. The device of claim 7 , 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.
9. The device of claim 8 , wherein the one or more inorganic additives comprises ZnO.
10. The device of claim 2 , further comprising an insulating film and a semiconductor substrate.
11. The device of claim 10 , wherein the insulating film comprises one or more components selected from: titanium oxide, silicon nitride, SiNx:H, silicon oxide, and silicon oxide/titanium oxide.
12. A solar cell comprising the semiconductor device of claim 2 .