Electroconductive thick film composition(s), electrode(s), and semiconductor device(s) formed therefrom
View Patent ↗The present invention is directed to an electroconductive thick film composition comprising: (a) electroconductive metal particles selected from (1) Al, Cu, Au, Ag, Pd and Pt; (2) alloy of Al, Cu, Au, Ag, Pd and Pt; and (3) mixtures thereof; (3) glass frit wherein said glass frit is Pb-free; dispersed in (d) an organic medium, and wherein the average diameter of said electroconductive metal particles is in the range of 0.5-10.0 μm. The present invention is further directed to an electrode formed from the composition as detailed above and a semiconductor device(s) (for example, a solar cell) comprising said electrode.
1. A thick film conductive composition comprising:
(a) electroconductive metal particles consisting essentially of Ag particles,
(b) glass frit wherein said glass frit is Pb-free, and wherein said glass frit comprises, in weight percent total glass frit composition: SiO 2 0.5-35, Al 2 O 3 0-5, B 2 O 3 1-15, ZnO 0-15, and Bi 2 O 3 55-90;
(c) one or more inorganic Cu additives, wherein said inorganic Cu additives are selected from the group consisting of (1) Cu; (2) compounds that can generate elemental Cu; (3) oxides of Cu; and (4) mixtures thereof; and
(d) one or more inorganic Bi additives, wherein said inorganic Bi additives are selected from the group consisting of (1) Bi; (2) compounds that can generate elemental Bi; (3) oxides of Bi; and (4) mixtures thereof; and
(e) an organic medium.
2. An electrode formed from the composition of claim 1 wherein said composition has been fired to remove the organic medium and sinter said glass frit.
3. A semiconductor device comprising the electrode of claim 2 .
4. The composition of claim 1 , wherein the glass frit is 2-6 wt % of the total composition.
5. The composition of claim 1 , wherein the average diameter of said electro conductive metal particles is in the range of 0.5-10.0 μm.
6. The composition of claim 1 further comprising one or more inorganic additives that are selected from the group consisting of (1) TiB2, Ti, Al, Sn, Sb, Cr, Fe, Mn, Co, Ni, Ru, and B; (2) compounds that can generate elemental metals selected from, Ti, Al, Sn, Sb, Cr, Fe, Mn, Co, Ni, Ru, B and; (3) oxides of, Ti, Al, Sn, Sb, Cr, Fe, Mn, Co, Ni, Ru, and B; and (4) mixtures thereof.
7. The composition of claim 1 comprising, based on weight percent total composition: 40-93 weight percent Ag particles, 2-10 weight percent of said glass frit, and 5-50 weight percent organic medium.
8. The thick film composition of claim 1 wherein said electroconductive metal particles are in the form selected from (1) flakes, (2) spherical and (3) mixtures thereof.
9. A thick film conductive composition comprising:
(a) electroconductive metal particles selected from the group consisting of Ag particles and Al particles and mixtures thereof,
(b) glass frit wherein said glass frit is Pb-free, and wherein said glass frit comprises, in weight percent total glass frit composition: SiO 2 0.5-35, Al 2 O 3 0-5, B 2 O 3 1-15, ZnO 0-15, and Bi 2 O 3 55-90;
(c) one or more inorganic Cu additives, wherein said inorganic Cu additives are selected from the group consisting of (1) Cu; (2) compounds that can generate elemental Cu; (3) oxides of Cu; and (4) mixtures thereof; and
(d) one or more inorganic Bi additives, wherein said inorganic Bi additives are selected from the group consisting of (1) Bi; (2) compounds that can generate elemental Bi; (3) oxides of Bi; and (4) mixtures thereof; and
(e) an organic medium.