Solar cell contact structures formed from metal paste
View Patent ↗Solar cell contact structures formed from metal paste and methods of forming solar cell contact structures from metal paste are described. In a first example, a solar cell includes a substrate. A semiconductor region is disposed in or above the substrate. A contact structure is disposed on the semiconductor region and includes a conductive layer in contact with the semiconductor region. The conductive layer includes a matrix binder having aluminum/silicon (Al/Si) particles and an inert filler material dispersed therein. In a second example, a solar cell includes a substrate. A semiconductor region is disposed in or above the substrate. A contact structure is disposed on the semiconductor region and includes a conductive layer in contact with the semiconductor region. The conductive layer includes an agent for increasing a hydrophobic characteristic of the conductive layer.
1. A solar cell, comprising:
a substrate;
a semiconductor region disposed in or above the substrate; and
a contact structure disposed on the semiconductor region and comprising a conductive layer in contact with the semiconductor region, the conductive layer comprising a matrix binder having aluminum/silicon (Al/Si) particles and an inert filler material dispersed therein the conductive layer comprising a moisture impermeable porous layer, a self-assembled monolayer (SAM) sealing filling the pores of the porous layer, wherein the SAM only exists within the pores.
2. The solar cell of claim 1 , wherein the conductive layer is an essentially crack-free conductive layer.
3. The solar cell of claim 1 , wherein the inert filler material is dispersed in spaces between the Al/Si particles.
4. The solar cell of claim 1 , wherein the inert filler material comprises fumed sub-micron silica particles.
5. The solar cell of claim 1 , wherein the semiconductor region is a polycrystalline silicon layer of an emitter region disposed above the substrate.
6. The solar cell of claim 1 , wherein the semiconductor region is a diffusion region disposed in the substrate, and wherein the substrate is a monocrystalline silicon substrate.
7. The solar cell of claim 1 , the contact structure further comprising:
a nickel (Ni) layer disposed on the conductive layer; and
a copper (Cu) layer disposed on the Ni layer.
8. The solar cell of claim 1 , wherein the solar cell is a back-contact solar cell.
9. A back contact solar cell, comprising:
a substrate;
a semiconductor region disposed in or above the substrate;
a contact structure disposed on the semiconductor region and comprising a conductive layer in contact with the semiconductor region, the conductive layer comprising a matrix binder having aluminum/silicon (Al/Si) particles and an inert filler material dispersed in spaces between the Al/Si particles, the inert filler material comprising fumed sub-micron silica particles, wherein the contact structure further comprises a first metal layer disposed on the conductive layer and a second metal layer disposed on the first metal layer the conductive layer comprising a moisture impermeable porous layer, a self-assembled monolayer (SAM) sealing filling the pores of the porous layer, wherein the SAM only exists within the pores.
10. The back contact solar cell of claim 9 , wherein the conductive layer is an essentially crack-free conductive layer.