PASSIVATION OF LIGHT-RECEIVING SURFACES OF SOLAR CELLS
Methods of passivating light-receiving surfaces of solar cells, and the resulting solar cells, are described. In an example, a solar cell includes a silicon substrate having a light-receiving surface. An intrinsic silicon layer is disposed above the light-receiving surface of the silicon substrate. An N-type silicon layer is disposed on the intrinsic silicon layer. A non-conductive anti-reflective coating (ARC) layer is disposed on the N-type silicon layer. In another example, a solar cell includes a silicon substrate having a light-receiving surface. A tunneling dielectric layer is disposed on the light-receiving surface of the silicon substrate. An N-type silicon layer is disposed on the tunneling dielectric layer. A non-conductive anti-reflective coating (ARC) layer is disposed on the N-type silicon layer.
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;
an N-type silicon layer disposed on the intrinsic silicon layer; and
a non-conductive anti-reflective coating (ARC) layer disposed on the N-type silicon layer.
2 . The solar cell of claim 1 , wherein the silicon substrate is a monocrystalline silicon substrate, wherein the intrinsic silicon layer is an intrinsic amorphous silicon layer, and wherein the N-type silicon layer is an N-type amorphous silicon layer.
3 . The solar cell of claim 1 , further comprising:
a tunneling dielectric layer disposed on the light-receiving surface of the silicon substrate, wherein the intrinsic silicon layer is disposed on the tunneling dielectric layer.
4 . The solar cell of claim 3 , wherein the tunneling dielectric layer is a layer of silicon dioxide (SiO 2 ).
5 . The solar cell of claim 4 , wherein the silicon substrate is a monocrystalline silicon substrate, wherein the intrinsic silicon layer is an intrinsic amorphous silicon layer, and wherein the N-type silicon layer is an N-type amorphous silicon layer.
6 . The solar cell of claim 5 , wherein the layer of silicon dioxide (SiO 2 ) has a thickness approximately in the range of 1-10 nanometers, and wherein the intrinsic amorphous silicon layer has a thickness approximately in the range of 1-5 nanometers.
7 . The solar cell of claim 1 , wherein the non-conductive anti-reflective coating (ARC) layer comprises silicon nitride.
8 . The solar cell of claim 1 , wherein the light-receiving surface has a texturized topography, and wherein the intrinsic silicon layer is conformal with the texturized topography of the light-receiving surface.
9 . 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 coupled to the plurality of alternating N-type and P-type semiconductor regions.
10 . A solar cell, comprising:
a silicon substrate having a light-receiving surface;
a tunneling dielectric layer disposed on the light-receiving surface of the silicon substrate;
an N-type silicon layer disposed on the tunneling dielectric layer; and
a non-conductive anti-reflective coating (ARC) layer disposed on the N-type silicon layer.
11 . The solar cell of claim 10 , wherein the silicon substrate is a monocrystalline silicon substrate, and wherein the N-type silicon layer is an N-type amorphous silicon layer.
12 . The solar cell of claim 10 , wherein the tunneling dielectric layer is a layer of silicon dioxide (SiO 2 ) having a thickness approximately in the range of 1-10 nanometers.
13 . The solar cell of claim 10 , wherein the non-conductive anti-reflective coating (ARC) layer comprises silicon nitride.
14 . The solar cell of claim 10 , wherein the light-receiving surface of the substrate has a texturized topography, and wherein the N-type silicon layer is conformal with the texturized topography of the light-receiving surface.
15 . The solar cell of claim 10 , 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 coupled 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 tunneling dielectric layer on a light-receiving surface of a silicon substrate; and
forming an amorphous silicon layer on the tunneling dielectric layer at a temperature less than approximately 300 degrees Celsius.
17 . The method of claim 16 , wherein forming the tunneling 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 ), 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.
18 . The method of claim 16 , wherein forming the amorphous silicon layer comprises forming an intrinsic amorphous silicon layer, the method further comprising:
forming an N-type amorphous silicon layer on the amorphous silicon layer at a temperature less than approximately 300 degrees Celsius; and
forming an anti-reflective coating (ARC) layer on the N-type amorphous silicon layer at a temperature less than approximately 300 degrees Celsius.
19 . The method of claim 16 , wherein forming the amorphous silicon layer comprises forming an N-type amorphous silicon layer, the method further comprising:
forming an anti-reflective coating (ARC) layer on the N-type amorphous silicon layer at a temperature less than approximately 300 degrees Celsius.
20 . A solar cell fabricated according to the method of claim 16 .