Electroconductive thick film composition(s), electrode(s), and semiconductor device(s) formed therefrom

Abstract

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 selected from the group consisting of (1) Al, Cu, Au, Ag, Pd and Pt; (2) alloy of Al, Cu, Au, Ag, Pd and Pt; and (3) mixtures thereof;   (b) glass frit wherein said glass frit is Pb-free; dispersed in   (c) an organic medium, and   
       wherein the average diameter of said electroconductive metal particles is in the range of 0.5-10.0 μm. 
     
     
         2 . The composition of  claim 1  wherein said electroconductive metal particles comprise Ag particles and Al particles. 
     
     
         3 . The composition of  claim 1  wherein said glass frit comprises, in weight percent total glass frit composition: SiO 2  0.5-35, Al 2 O 3  0-5, B2O3 1-15, ZnO 0-15, and Bi 2 O 3  55-90. 
     
     
         4 . The composition of  claim 1  further comprising inorganic additives. 
     
     
         5 . The composition of  claim 4  wherein said inorganic additives are selected from the group consisting of (1) TiB2, Cu, Ti, Al, Sn, Sb, Cr, Fe, Mn, Co, Ni, Ru, B and Bi; (2) compounds that can generate elemental metals selected from Cu, Ti, Al, Sn, Sb, Cr, Fe, Mn, Co, Ni, Ru, B and Bi; (3) oxides of Cu, Ti, Al, Sn, Sb, Cr, Fe, Mn, Co, Ni, Ru, B and Bi; and (4) mixtures thereof. 
     
     
         6 . The composition of  claim 2  comprising, based on weight percent total composition: 40-93 weight percent Ag particles, 2-10 weight percent of said glass frit, 1-5 weight percent Al particles and 5-50 weight percent organic medium. 
     
     
         7 . 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. 
     
     
         8 . The thick film composition of any one of  claim 1  or  2  wherein the softening point of said glass frit is in the range of 300°-550° C. 
     
     
         9 . 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. 
     
     
         10 . A semiconductor device comprising the electrode of  claim 9 .