Thick-film conductive compositions with nano-sized zinc additive
View Patent ↗The present invention is a thick film silver composition for use a solar cell device. The thick film paste composition comprises an electrically conductive silver powder, one or more glass frits, a nano-sized additive wherein the nano-sized additive is selected from metallic zinc, zinc alloys or a mixture of metallic zinc and zinc oxide, all dispersed in an organic medium.
1. A thick film paste composition comprising, based on solids:
a) 80 to 99% by weight of an electrically conductive silver powder;
b) 0.1 to 10% by weight of one or more glass frit;
c) 0.1 to 10% by weight of a nano-sized, spherical zinc additive having a specific surface area between 4 m 2 /gr to 6 m 2 /gr and a particle size of 1.0 to 125 nm, wherein the zinc additive is a mixture of metallic zinc and zinc oxide; dispersed in
d) an organic medium.
2. The composition of claim 1 , wherein the glass frit comprises Bi 2 O 3 or B 2 O 3 .
3. The composition of claim 1 , wherein the glass frit comprises one or more components selected from the group consisting of SiO 2 , P 2 O 5 , GeO 2 , and V 2 O 5 .