Method for fabricating solar cell element
View Patent ↗A method for fabricating a solar cell element, the method comprising a step (a) of preparing a laminate and a chamber, a step (b) of bringing the laminate into contact with the aqueous solution in such a manner that the second surface is immersed in the aqueous solution after the step (a); a step (c) of applying a voltage difference between an anode electrode and the laminate under an atmosphere of the inert gas to form a Zn layer on the second surface after the step (b); and a step (d) of exposing the Zn layer to oxygen so as to convert the Zn layer into a ZnO crystalline layer after the step (c).
1. A method for fabricating a solar cell element, the method comprising:
a step (a) of preparing a laminate and a chamber, wherein:
the laminate comprises a p-side group-III-group-V compound electrode layer, a p-type group-III-group-V compound semiconductor layer, an n-type group-III-group-V compound semiconductor layer, and an n-side group-III-group-V compound electrode layer,
the n-side group-III-group-V compound electrode layer comprises a first surface and a second surface,
the p-type group-III-group-V compound semiconductor layer is interposed between the p-side group-III-group-V compound electrode layer and the n-type group-III-group-V compound semiconductor layer,
the n-type group-III-group-V compound semiconductor layer is interposed between the p-type group-III-group-V compound semiconductor layer and the first surface,
the second surface is exposed on the surface of the laminate, and
the chamber has an aqueous solution and an inert gas;
a step (b) of bringing the laminate into contact with the aqueous solution in such a manner that the second surface is immersed in the aqueous solution after the step (a);
a step (c) of applying a voltage difference between an anode electrode and the laminate under an atmosphere of the inert gas to form a Zn layer on the second surface after the step (b), wherein:
the chamber is filled with the inert gas,
the aqueous solution contains Zn 2+ ions having a concentration of not less than 1 mM and not more than 5 M,
no oxygen gas is dissolved in the aqueous solution,
the anode electrode is contact with the aqueous solution,
the laminate is used as a cathode electrode,
a temperature of the aqueous solution is not less than 10 degrees Celsius and not more than 60 degrees Celsius, and
the Zn layer has a concave-convex structure on the surface thereof; and
a step (d) of exposing the Zn layer to oxygen so as to convert the Zn layer into a ZnO crystalline layer after the step (c).
2. The method according to the claim 1 , wherein
in the step (d), the Zn layer is exposed to air.
3. The method according to the claim 1 , wherein:
in the step (a), the n-side group-III-group-V compound electrode layer comprises a GaAs layer, and
a surface of the GaAs layer is the second surface.
4. A method comprising a step of electrodepositing a Zn layer on an electrode by using an aqueous solution containing Zn 2+ , wherein:
no oxygen gas is dissolved in the aqueous solution, and
the electrode comprises a III-V semiconductor.
5. The method of claim 4 , wherein the step of electrodepositing is performed in a chamber that contains the aqueous solution and is filled with an inert gas.
6. The method of claim 4 , wherein a temperature of the aqueous solution is not less than 10 degrees Celsius and not more than 60 degrees Celsius.
7. The method of claim 4 , wherein a concentration of Zn 2+ ions in the aqueous solution is not less than 1 mM and not more than 5 M.
8. The method of claim 4 , wherein the II-V semiconductor comprises GaAs.