SOLAR CELL WITH METAL GRID FABRICATED BY ELECTROPLATING

1 . A method for fabricating a solar cell, comprising:

forming a photovoltaic structure;

forming a layer of transparent-conductive-oxide (TCO) situated above the photovoltaic structure;

forming a front-side electrode grid situated above the TCO layer by:

depositing, using a physical vapor deposition (PVD) technique, one or more metal layers; and

depositing, using an electroplating technique, a copper layer situated above the one or more PVD-deposited metal layers; and

forming a back-side electrode.

2 . The method of claim 1 , wherein forming the photovoltaic structure further comprising depositing one or more layers of amorphous-Si (a-Si) above a crystalline Si (c-Si) substrate, and wherein the a-Si layers includes at least one of:

a layer of heavily doped a-Si;

a layer of intrinsic a-Si; and

an a-Si layer with graded doping.

3 . The method of claim 2 , wherein the c-Si substrate is n-type doped, and wherein the heavily doped a-Si layer and the graded doped a-Si layer are p-type doped.

4 . The method of claim 1 , wherein a resistivity of the front-side electrode grid is less than 2×10 −5 Ω·cm.

5 . The method of claim 1 , further comprising depositing, using a electroplating technique, one or more metal layers above the electroplated copper layer, wherein the one or more electroplated metal layers include one or more of:

a layer of Ni;

a layer of Sn; and

a layer of Ag.

6 . The method of claim 1 , wherein electroplating the copper layer further involves depositing and/or removing a patterned masking layer above the TCO layer.

7 . The method of claim 1 , wherein the TCO layer comprises at least one of:

indium-tin-oxide (ITO);

aluminum-doped zinc-oxide (ZnO:Al);

gallium-doped zinc-oxide (ZnO:Ga);

tungsten-doped indium oxide (IWO); and

Zn—In—Sn—O (ZITO).

8 . The method of claim 1 , wherein the photovoltaic structure includes at least one of:

a homogeneous junction;

a heterojunction;

a heterotunneling junction; and

multiple p-n junctions.

9 . The method of claim 1 , wherein the back-side electrode comprises a metal grid which can be connected lines or a continuous layer.

10 . The method of claim 9 , wherein the metal grid is formed using at least one of the following techniques:

screen-printing;

electroplating;

physical vapor deposition including evaporation and sputtering deposition; and

aerosol-jet printing.

11 . The method of claim 1 , further comprising:

forming a back-side TCO layer beneath the photovoltaic structure, wherein the back-side TCO layer is in contact with a back surface of the photovoltaic structure.

12 . The method of claim 11 , wherein forming the back-side electrode comprises depositing a seed metal layer beneath the back-side TCO layer, wherein the seed metal layer includes at least one of: Cu, Ni, Ag, Ti, Ta, W, NiV, TiN, TaN, WN, TiW, and NiCr.

13 . The method of claim 1 , wherein the PVD technique includes one of: evaporation and sputtering deposition.

14 . The method of claim 1 , wherein the one or more PVD metal layers includes one or more layers of:

Cu, Ni, Ag, Ti, Ta, W, NiV, TiN, TaN, WN, TiW, and NiCr.