Method of stabilizing hydrogenated amorphous silicon and amorphous hydrogenated silicon alloys
A method of forming a semiconductor material of a photovoltaic device that includes providing a surface of a hydrogenated amorphous silicon containing material, and annealing the hydrogenated amorphous silicon containing material in a deuterium containing atmosphere. Deuterium from the deuterium-containing atmosphere is introduced to the lattice of the hydrogenated amorphous silicon containing material through the surface of the hydrogenated amorphous silicon containing material. In some embodiments, the deuterium that is introduced to the lattice of the hydrogenated amorphous silicon containing material increases the stability of the hydrogenated amorphous silicon containing material.
1. A method of forming a photovoltaic device comprising:
providing a crystalline doped semiconductor material having a first surface and a second surface opposite said first surface, wherein a layer of hydrogenated amorphous silicon containing material is disposed across an entirety of said first surface and second surface of said crystalline doped semiconductor material; and
annealing each layer of said hydrogenated amorphous silicon containing material at a temperature from 100° C. to 400° C. and in a deuterium containing atmosphere selected from the group consisting of 100% deuterium (D 2 ), and deuterium (D 2 ) in combination with at least one gas selected from the group consisting of helium, argon, krypton, nitrogen and combinations thereof, wherein deuterium is introduced to a lattice of each layer of said hydrogenated amorphous silicon containing material.
2. The method of claim 1 , wherein each layer of said hydrogenated amorphous silicon containing material is deposited using a plasma enhanced chemical vapor deposition process.
3. The method of claim 2 , wherein precursor gases of the plasma enhanced chemical vapor deposition process includes a silane containing gas and hydrogen containing gas.
4. The method of claim 3 , wherein the capacitive discharges are provided by an RF power density greater than 2 mW/cm 2 .
5. The method of claim 4 , wherein the plasma enhanced chemical vapor deposition process comprises a temperature ranging from 100° C. to 400° C., and a pressure ranging from 20 mtorr to 10 torr.
6. The method of claim 1 , wherein each layer of said hydrogenated amorphous silicon containing material is selected from the group consisting of hydrogenated amorphous silicon, hydrogenated amorphous silicon germanium, hydrogenated amorphous silicon carbide, and combinations thereof.
7. The method of claim 1 , wherein the deuterium containing atmosphere comprises a deuterium containing gas flow ranging from 1 sccm to 500 sccm.
8. The method of claim 1 , wherein the annealing of each layer of said hydrogenated amorphous silicon containing material in the deuterium containing atmosphere comprises a pressure greater than 5 atmospheres.
9. The method of claim 1 , wherein the deuterium that is introduced to the lattice of each layer of said hydrogenated amorphous silicon containing material provides a deuterium treated hydrogenated amorphous silicon containing material comprising greater than 90 at. % silicon, greater than 5 at. % hydrogen and greater than 0.001 at. % deuterium.
10. The method of claim 9 , wherein each layer of said hydrogenated amorphous silicon containing material that includes the deuterium in the lattice of the hydrogenated amorphous silicon containing material is an intrinsic layer of a p-i-n photovoltaic cell.
11. The method of claim 9 , wherein each layer of said hydrogenated amorphous silicon containing material that includes the deuterium in the lattice of the hydrogenated amorphous silicon containing material is a contact layer of a heterojunction solar cell.
12. The method of claim 1 , wherein the annealing each layer of said hydrogenated amorphous silicon containing material in the deuterium containing atmosphere comprises a pressure greater than 20 atmospheres.
13. The method of claim 9 , wherein each layer of said hydrogenated amorphous silicon containing material that includes the deuterium in the lattice of the hydrogenated amorphous silicon containing material is a doped layer of a p-i-n photovoltaic cell.
14. The method of claim 13 , wherein said doped layer of said hydrogenated amorphous silicon containing material that includes the deuterium has a same conductivity as said a crystalline doped semiconductor material.
15. The method of claim 13 , wherein said doped layer of said hydrogenated amorphous silicon containing material that includes the deuterium has a different conductivity as said a crystalline doped semiconductor material.