PASSIVATION OF LIGHT-RECEIVING SURFACES OF SOLAR CELLS WITH CRYSTALLINE SILICON

1 . A solar cell, comprising:

a silicon substrate having a light-receiving surface;

an intrinsic silicon layer disposed above the light-receiving surface of the silicon substrate; and

an N-type silicon layer disposed on the intrinsic silicon layer, wherein one or both of the intrinsic silicon layer and the N-type silicon layer is a micro- or poly-crystalline silicon layer.

2 . The solar cell of claim 1 , wherein the N-type silicon layer is an N-type micro- or poly-crystalline silicon layer having a crystalline fraction approximately in the range of 0.1-0.9, with the balance being amorphous.

3 . The solar cell of claim 2 , wherein a concentration of N-type dopants in the N-type micro- or poly-crystalline silicon layer is approximately in the range of 1E17-1E20 atoms/cm 3 .

4 . The solar cell of claim 1 , further comprising:

a passivating dielectric layer disposed on the light-receiving surface of the silicon substrate, wherein the intrinsic silicon layer is disposed on the passivating dielectric layer.

5 . The solar cell of claim 4 , wherein the passivating dielectric layer is a layer of silicon dioxide (SiO 2 ) having a thickness approximately in the range of 10-200 Angstroms.

6 . The solar cell of claim 1 , further comprising:

an anti-reflective coating (ARC) layer disposed on the N-type silicon layer.

7 . The solar cell of claim 1 , wherein the light-receiving surface has a texturized topography, and wherein both the intrinsic silicon layer and the N-type silicon layer are conformal with the texturized topography of the light-receiving surface.

8 . The solar cell of claim 1 , wherein the substrate further comprises a back surface opposite the light-receiving surface, the solar cell further comprising:

a plurality of alternating N-type and P-type semiconductor regions at or above the back surface of the substrate; and

a conductive contact structure electrically connected to the plurality of alternating N-type and P-type semiconductor regions.

9 . A solar cell, comprising:

a silicon substrate having a light-receiving surface;

a passivating dielectric layer disposed on the light-receiving surface of the silicon substrate; and

an N-type micro- or poly-crystalline silicon layer disposed on the passivating dielectric layer.

10 . The solar cell of claim 9 , wherein the N-type micro- or poly-crystalline silicon layer has a crystalline fraction approximately in the range of 0.1-0.9, with the balance being amorphous.

11 . The solar cell of claim 10 , wherein a concentration of N-type dopants in the N-type micro- or poly-crystalline silicon layer is approximately in the range of 1e17-1e20 atoms/cm 3 .

12 . The solar cell of claim 9 , further comprising:

an anti-reflective coating (ARC) layer disposed on the N-type micro- or poly-crystalline silicon layer.

13 . The solar cell of claim 9 , wherein the passivating dielectric layer is a layer of silicon dioxide (SiO 2 ) having a thickness approximately in the range of 10-200 Angstroms.

14 . The solar cell of claim 9 , wherein the light-receiving surface of the substrate has a texturized topography, and wherein the N-type micro- or poly-crystalline silicon layer is conformal with the texturized topography of the light-receiving surface.

15 . The solar cell of claim 9 , wherein the substrate further comprises a back surface opposite the light-receiving surface, the solar cell further comprising:

a plurality of alternating N-type and P-type semiconductor regions at or above the back surface of the substrate; and

a conductive contact structure electrically connected to the plurality of alternating N-type and P-type semiconductor regions.

16 . A method of fabricating a solar cell, the method comprising:

forming a passivating dielectric layer on a light-receiving surface of a silicon substrate;

forming an N-type micro- or poly-crystalline silicon layer above the passivating dielectric layer; and

forming an anti-reflective coating (ARC) layer on the N-type micro- or poly-crystalline silicon layer.

17 . The method of claim 16 , wherein forming an N-type micro- or poly-crystalline silicon layer comprises depositing an N-type amorphous silicon layer and, subsequently, phase converting the N-type amorphous silicon layer to the N-type micro- or poly-crystalline silicon layer.

18 . The method of claim 16 , wherein forming an N-type micro- or poly-crystalline silicon layer comprises depositing the N-type micro- or poly-crystalline silicon layer.

19 . The method of claim 16 , further comprising:

forming an intrinsic micro- or poly-crystalline or amorphous silicon layer on the passivating dielectric layer, wherein forming the N-type micro- or poly-crystalline silicon layer comprises forming on the intrinsic micro- or poly-crystalline or amorphous silicon layer.

20 . The method of claim 16 , wherein forming the passivating dielectric layer comprises using a technique selected from the group consisting of chemical oxidation of a portion of the light-receiving surface of the silicon substrate, plasma-enhanced chemical vapor deposition (PECVD) of silicon dioxide (SiO 2 ), atomic layer deposition (ALD) of SiO 2 or AlOx, thermal oxidation of a portion of the light-receiving surface of the silicon substrate, and exposure of the light-receiving surface of the silicon substrate to ultra-violet (UV) radiation in an O 2 or O 3 environment.

21 . (canceled)