Low viscosity precursor compositions and methods for the deposition of conductive electronic features
A precursor composition for the deposition and formation of an electrical feature such as a conductive feature. The precursor composition advantageously has a low viscosity enabling deposition using direct-write tools. The precursor composition also has a low conversion temperature, enabling the deposition and conversion to an electrical feature on low temperature substrates. A particularly preferred precursor composition includes silver metal for the formation of highly conductive silver features.
1 . A process for repairing a damaged solar cell, comprising:
(a) providing the damaged solar cell comprising a damaged conductive feature disposed on a semiconductor, the damaged conductive feature comprising a damaged region;
(b) direct printing a precursor composition onto the damaged solar cell in the damaged region; and
(c) converting the precursor composition to a conductor by heating the precursor composition to a conversion temperature, thereby forming a repaired conductive feature.
2 . The process of claim 1 , wherein the direct printing comprises syringe dispensing.
3 . The process of claim 1 , wherein the direct printing comprises aerosol jet deposition.
4 . The process of claim 1 , wherein the direct printing comprises ink jet printing.
5 . The process of claim 1 , wherein a laser is used to heat the precursor composition.
6 . The process of claim 1 , wherein the damaged conductive feature was formed by screen-printing or photopatterning of a particle-containing composition.
7 . The process of claim 1 , wherein the conductor is laser trimmed.
8 . The process of claim 1 , wherein the process further comprises surface modifying the damaged solar cell with a laser.
9 . The process of claim 1 , wherein the repaired conductive feature has a minimum feature size that is not greater than about 250 μm.
10 . The process of claim 1 , wherein the repaired conductive feature has a minimum feature size that is not greater than about 100 μm.
11 . The process of claim 1 , wherein the repaired conductive feature has a minimum feature size that is not greater than about 10 μm.
12 . The process of claim 1 , wherein the heating comprises heating the precursor composition to a temperature not greater than 225° C. to form the solar cell conductive feature on the substrate.
13 . The process of claim 1 , wherein the heating comprises heating the precursor composition to a temperature not greater than 185° C. to form the solar cell conductive feature on the substrate.
14 . The process of claim 1 , wherein the repaired conductive feature comprises a set of finger lines and collector lines deposited essentially at a right angle to the finger lines.
15 . The process of claim 14 , wherein either or both the parallel finger lines or the collector lines have a width less than 200 μm.
16 . The process of claim 14 , wherein either or both the parallel finger lines or the collector lines have a width less than 100 μm.
17 . The process of claim 1 , wherein the precursor composition comprises metal oxide particles.
18 . The process of claim 1 , wherein the precursor composition comprises glass particles.
19 . The process of claim 1 , wherein the conductor has a thickness greater than 5 μm.
20 . The process of claim 1 , wherein the conductor comprises a transparent conductive feature.
21 . The process of claim 1 , wherein the conductor comprises a indium-tin oxide or antimony-tin oxide.
22 . The process of claim 1 , wherein the precursor composition comprises a metal precursor compound to a metal.
23 . The process of claim 22 , wherein the metal is selected from the group consisting of silver, palladium, copper, gold, platinum and nickel.
24 . The process of claim 1 , wherein the precursor composition comprises metallic particles comprising a metal.
25 . The process of claim 24 , wherein the metal is selected from the group consisting of silver, palladium, copper, gold, platinum and nickel.
26 . The process of claim 24 , wherein the metallic particles have a volume median particle size of not greater than 100 nanometers.
27 . The process of claim 24 , wherein the metallic particles have a volume median particle size of not greater than 0.3 μm.
28 . The process of claim 27 , wherein the metallic particles comprise a cap or coating thereon.
29 . The process of claim 28 , wherein the cap or coating comprises an inorganic cap or coating.
30 . The process of claim 28 , wherein the cap or coating comprises silica.
31 . The process of claim 28 , wherein the cap or coating comprises glass.
32 . The process of claim 28 , wherein the cap or coating comprises an organic cap or coating.
33 . The process of claim 28 , wherein the cap or coating comprises a polymer.
34 . The process of claim 28 , wherein the cap or coating comprises an intrinsically conductive polymer, a sulfonated perfluorohydrocarbon polymer, polystyrene, polystyrene/methacrylate, sodium bis(2-ethylhexyl) sulfosuccinate, tetra-n-octyl-ammonium bromide or an alkane thiolate.
35 . The process of claim 28 , wherein the cap or coating comprises PVP.
36 . The process of claim 27 , wherein the conductivity of the conductor is no less than 10 percent the conductivity of the equivalent pure metal.
37 . The process of claim 27 , wherein the conductor has a resistivity that is not greater than 4 times the resistivity of the equivalent pure metal.
38 . The process of claim 27 , wherein the conductor has a resistivity that is not greater than 2 times the resistivity of the equivalent pure metal.
39 . The process of claim 1 , wherein the conductor is resistant to solder leaching.
40 . The process of claim 1 , wherein the process further comprises high shear mixing the precursor composition.
41 . The process of claim 1 , wherein the conductor comprises a metal-glass composition.
42 . A process for repairing a solar cell, comprising ink jet printing a precursor composition onto a damaged region of the solar cell and heating the printed precursor composition to form a repaired region.
43 . The process of claim 42 , wherein a laser is used to heat the precursor composition.
44 . The process of claim 42 , wherein the solar cell was formed by screen-printing or photopatterning of a particle-containing composition.
45 . The process of claim 42 , wherein the repaired region is laser trimmed.
46 . The process of claim 42 , wherein the process further comprises surface modifying the damaged region with a laser.
47 . The process of claim 42 , wherein the repaired region has a minimum feature size that is not greater than about 250 μm.
48 . The process of claim 42 , wherein the repaired region has a minimum feature size that is not greater than about 100 μm.
49 . The process of claim 42 , wherein the repaired region has a minimum feature size that is not greater than about 10 μm.
50 . The process of claim 42 , wherein the heating comprises heating the precursor composition to a temperature not greater than 225° C. to form the repaired region.
51 . The process of claim 42 , wherein the heating comprises heating the precursor composition to a temperature not greater than 185° C. to form the repaired region.
52 . The process of claim 42 , wherein the repaired region comprises a set of finger lines and collector lines deposited essentially at a right angle to the finger lines.
53 . The process of claim 52 , wherein either or both the parallel finger lines or the collector lines have a width less than 200 μm.
54 . The process of claim 52 , wherein either or both the parallel finger lines or the collector lines have a width less than 100 μm.
55 . The process of claim 42 , wherein the precursor composition comprises metal oxide particles.
56 . The process of claim 42 , wherein the precursor composition comprises glass particles.
57 . The process of claim 42 , wherein the repaired region has a thickness greater than 5 μm.
58 . The process of claim 42 , wherein the repaired region comprises a transparent conductive feature.
59 . The process of claim 42 , wherein the repaired region comprises a indium-tin oxide or antimony-tin oxide.
60 . The process of claim 42 , wherein the precursor composition comprises a metal precursor compound to a metal.
61 . The process of claim 60 , wherein the metal is selected from the group consisting of silver, palladium, copper, gold, platinum and nickel.
62 . The process of claim 42 , wherein the precursor composition comprises metallic particles comprising a metal.
63 . The process of claim 62 , wherein the metal is selected from the group consisting of silver, palladium, copper, gold, platinum and nickel.
64 . The process of claim 62 , wherein the metallic particles have a volume median particle size of not greater than 100 nanometers.
65 . The process of claim 62 , wherein the metallic particles have a volume median particle size of not greater than 0.3 μm.
66 . The process of claim 65 , wherein the metallic particles comprise a cap or coating thereon.
67 . The process of claim 66 , wherein the cap or coating comprises an inorganic cap or coating.
68 . The process of claim 66 , wherein the cap or coating comprises silica.
69 . The process of claim 66 , wherein the cap or coating comprises glass.
70 . The process of claim 66 , wherein the cap or coating comprises an organic cap or coating.
71 . The process of claim 66 , wherein the cap or coating comprises a polymer.
72 . The process of claim 66 , wherein the cap or coating comprises an intrinsically conductive polymer, a sulfonated perfluorohydrocarbon polymer, polystyrene, polystyrene/methacrylate, sodium bis(2-ethylhexyl) sulfosuccinate, tetra-n-octyl-ammonium bromide or an alkane thiolate.
73 . The process of claim 66 , wherein the cap or coating comprises PVP.
74 . The process of claim 62 , wherein the conductivity of the repaired region is no less than 10 percent the conductivity of the equivalent pure metal.
75 . The process of claim 62 , wherein the repaired region has a resistivity that is not greater than 4 times the resistivity of the equivalent pure metal.
76 . The process of claim 62 , wherein the repaired region has a resistivity that is not greater than 2 times the resistivity of the equivalent pure metal.
77 . The process of claim 42 , wherein the repaired region is resistant to solder leaching.
78 . The process of claim 42 , wherein the process further comprises high shear mixing the precursor composition.
79 . The process of claim 42 , wherein the repaired region comprises a metal-glass composition.