Solar cell with high aspect ratio gridlines supported between co-extruded support structures
View Patent ↗A solar cell structure formed by extruding/dispensing materials on a substrate such that centrally disposed conductive high aspect ratio line structures (gridlines) are formed on the substrate surface with localized support structures coincidentally disposed on opposing side surfaces of the gridlines such that the gridlines are surrounded or otherwise supported by the localized support structures. In one embodiment the localized support structures are transparent, remain on the substrate after the co-extrusion process, and are covered by a layer of material. In another embodiment, the localized support structures are sacrificial support structures that are removed as part of the solar cell structure manufacturing process. In both cases the co-extrusion process is performed such that both the central gridline and the localized support structures are in direct contact with the surface of the substrate.
1. An intermediate structure comprising:
a substrate; and
a plurality of parallel gridlines on the substrate, wherein each of the plurality of parallel gridlines includes:
a central line structure comprising a first non-Newtonian fluid and having an aspect ratio, wherein the first non-Newtonian fluid comprises a silver paste, and
a sacrificial support structure comprising a second non-Newtonian fluid, wherein the second non-Newtonian fluid is in contact with the first non-Newtonian fluid such that side portions of the sacrificial support structure contact opposing side edges of the central line structure, wherein the second non-Newtonian fluid is configured to maintain a cross sectional shape of the central line structure, and
wherein each sacrificial support structure is localized to only a single gridline;
wherein the central line structure of all of the plurality of parallel gridlines cover less than 4% of a surface area of said substrate.
2. The intermediate structure of claim 1 , wherein the central line structure of each of the plurality of parallel gridlines has an aspect ratio greater than 2:1.
3. The intermediate structure of claim 1 , wherein the central line structure of each of the plurality of parallel gridlines has a width in the range of 100 nanometers to 100 microns.
4. The intermediate structure of claim 1 , wherein both the central line structure and the sacrificial support structure of each of the plurality of parallel gridlines are in direct contact with a surface of the substrate.
5. The intermediate structure of claim 1 , wherein the second non-Newtonian fluid has substantially the same rheology to that of the silver paste.
6. An intermediate structure comprising:
a substrate having a surface with a plurality of
elongated composite structures on the surface of the substrate, each
composite structure comprising a central line structure:
the central line structure comprising a first co-extruded non-Newtonian fluid,
wherein the first co-extruded non-Newtonian fluid comprises a silver paste, and
a sacrificial support structure comprising a second co-extruded non-Newtonian fluid that is disposed on the central line structure such that side portions of the support structure are horizontally adjacent to the central line structure without substantial intermixing of the first co-extruded non-Newtonian fluid and second co-extruded non-Newtonian fluid, and wherein the second co-extruded non-Newtonian fluid is configured to maintain a cross sectional shape of the central line structure,
wherein both the side portions of the sacrificial support structure and the central line structure are in direct contact with the surface of the substrate, and wherein each sacrificial support structure is localized to only a single central line structure;
wherein the plurality of central line structures cover less than 4% of a surface area of said substrate.
7. The intermediate structure of claim 6 , wherein the central line structure has an aspect ratio greater than 2:1.
8. The intermediate structure of claim 6 , wherein the central line structure has a width in the range of 100 nanometers to 100 microns.
9. The intermediate structure of claim 6 , wherein the second non-Newtonian fluid has a closely matched rheology to that of the silver paste.
10. The intermediate structure of claim 6 , wherein the central line structure comprises a multilayer stack.
11. The intermediate structure of claim 6 , wherein the support structure is configured to be removed after any one of drying, curing and sintering.