Electroconductive Paste Composition Containing Metal Nanoparticles
An electroconductive paste composition, particularly for solar cells, contains silver particles, glass frit, an organic vehicle, and a nanoparticle additive. The additive contains electrically conductive metal, metal alloy, and/or metal silicide nanoparticles, such as nickel, chromium, cobalt, titanium, or alloys, silicides, and mixtures thereof. When used to form an electrical contact on a solar cell, such a paste provides for decreased contact resistance between the paste and the substrate and improved efficiency of the solar cell.
1 . An electroconductive paste composition comprising:
(a) silver particles;
(b) glass frit;
(c) electrically conductive metal, metal alloy, and/or metal silicide nanoparticles, wherein the nanoparticles have a particle diameter of about 5 nm to about 2 microns; and
(d) an organic vehicle.
2 . The composition according to claim 1 , wherein the nanoparticles comprise at least one selected from the group consisting of nickel, chromium, cobalt, titanium, and alloys, silicides, and mixtures thereof.
3 . The composition according to claim 1 , comprising about 40 to about 95% silver particles, about 0.5 to about 6% glass frit, about 0.05 to 20 wt % metal nanoparticles, and about 5 to about 30% organic vehicle, all percentages being by weight based on a total weight of the composition.
4 . The composition according to claim 1 , wherein the nanoparticles have a particle diameter of about 20 nm to about 800 nm.
5 . The composition according to claim 4 , wherein the nanoparticles have a particle diameter of about 20 nm to about 500 nm.
6 . The composition according to claim 1 , wherein the nanoparticles are present in the composition in an amount of about 0.05 to about 20% by weight based on a total weight of the composition.
7 . The composition according to claim 6 , wherein the nanoparticles are present in an amount of about 0.05 to 10.0 wt %.
8 . The composition according to claim 7 , wherein the nanoparticles are present in an amount of about 0.05 to 5.0 wt %.
9 . The composition according to claim 1 , further comprising at least one additive selected from the group consisting of Al 2 O 3 , ZnO, Li 2 O, Ag 2 O, AgO, MoO 3 , TiO 2 , TeO 2 , CoO, Co 2 O 3 , Bi 2 O 3 , CeO 2 , CeF 4 , SiO 2 , MgO, PbO, ZrO 2 , HfO 2 , In 2 O 3 , SnO 2 , P 2 O 5 , Ta 2 O 5 , B 2 O 3 , Ag 3 PO 4 , LiCoO 2 , LiNiO 2 , Ni 3 (PO 4 ) 2 , NiO, or lithium phosphates in an amount of about 0.1 to 3.0 wt %.
10 . A solar cell electrode formed by applying an electroconductive paste composition to a substrate and firing the paste to form the electrode, wherein the electroconductive paste composition comprises:
(a) silver particles;
(b) glass frit;
(c) electrically conductive metal, metal alloy, and/or metal silicide nanoparticles, wherein the nanoparticles have a particle diameter of about 5 nm to about 2 microns; and
(d) an organic vehicle.
11 . The solar cell electrode according to claim 10 , wherein the nanoparticles are at least one selected from the group consisting of nickel, chromium, cobalt, titanium, and alloys, silicides, and mixtures thereof.
12 . The solar cell electrode according to claim 10 , wherein the nanoparticles have a particle diameter of about 20 nm to about 800 nm.
13 . The solar cell electrode according to claim 12 , wherein the nanoparticles have a particle diameter of about 20 nm to about 500 nm.
14 . The solar cell electrode according to claim 10 , wherein the nanoparticles are present in the composition in an amount of about 0.05 to about 20% by weight based on a total weight of the composition.
15 . The solar cell electrode according to claim 14 , wherein the nanoparticles are present in an amount of about 0.05 to 10.0 wt %.
16 . The solar cell electrode according to claim 15 , wherein the nanoparticles are present in an amount of about 0.05 to 5.0 wt %.
17 . The solar cell electrode according to claim 10 , wherein the electroconductive paste composition further comprises at least one additive selected from the group consisting of Al 2 O 3 , ZnO, Li 2 O, Ag 2 O, AgO, MoO 3 , TiO 2 , TeO 2 , CoO, Co 2 O 3 , Bi 2 O 3 , CeO 2 , CeF 4 , SiO 2 , MgO, PbO, ZrO 2 , HfO 2 , In 2 O 3 , SnO 2 , P 2 O 5 , Ta 2 O 5 , B 2 O 3 , Ag 3 PO 4 , LiCoO 2 , LiNiO 2 , Ni 3 (PO 4 ) 2 , NiO, or lithium phosphate in an amount of about 0.1 to 3.0 wt %.
18 . A solar cell electrode formed by applying a first layer of a first electroconductive paste composition to a substrate and drying the paste, applying a second layer of a second electroconductive paste composition to the first layer, and firing the two layers to form the electrode, wherein the first electroconductive paste composition comprises:
(a) silver particles;
(b) glass frit;
(c) electrically conductive metal, metal alloy, and/or metal silicide nanoparticles, wherein the nanoparticles have a particle diameter of about 5 nm to about 2 microns; and
(d) an organic vehicle;
and wherein the second electroconductive paste is the same as or different from the first electroconductive paste.
19 . The solar cell electrode according to claim 18 , wherein the nanoparticles are at least one selected from the group consisting of nickel, chromium, cobalt, titanium, and alloys, silicides, and mixtures thereof.
20 . A method of forming a solar cell electrode comprising applying a layer of a first electroconductive paste composition to a substrate and firing the paste to form the electrode, wherein the first electroconductive paste composition comprises:
(a) silver particles;
(b) glass frit;
(c) electrically conductive, metal, metal alloy, and/or metal silicide nanoparticles, wherein the nanoparticles have a particle diameter of about 5 nm to about 2 microns; and
(d) an organic vehicle.
21 . The method according to claim 20 , wherein the nanoparticles are at least one selected from the group consisting of nickel, chromium, cobalt, titanium, and alloys, silicides, and mixtures thereof.
22 . The method according to claim 20 , further comprising forming a layer of a second electroconductive paste composition on the layer of the first electroconductive paste composition.