Solar cell
A method of fabricating a solar cell includes steps of: forming an amorphous carbon layer, an AlN layer and a first n-type nitride semiconductor layer on the surface of the graphite substrate, forming a mask layer with a plurality of openings on the first n-type nitride semiconductor layer; forming a plurality of second n-type nitride semiconductor layers on the portions of the first n-type nitride semiconductor layer which are exposed by the plurality of openings; forming a plurality of light absorption layers on the plurality of second n-type nitride semiconductor layers; forming a plurality of p-side nitride semiconductor layers on the plurality of the light absorption layers; forming a p-side electrode; and forming an n-side electrode.
1. A method of fabricating a solar cell, the method comprising steps of:
performing an oxygen-ashing treatment to a surface of a graphite substrate to form an amorphous carbon layer on the surface of the graphite substrate;
forming an AlN layer on the amorphous carbon layer by a Metal Organic Chemical Vapor Deposition (MOCVD) method;
forming a first n-type nitride semiconductor layer on the AlN layer;
forming a mask layer with a plurality of openings on the first n-type nitride semiconductor layer;
forming a plurality of second n-type nitride semiconductor layers on portions of the first n-type nitride semiconductor layer which are exposed by the plurality of openings;
forming a plurality of light absorption layers on the plurality of second n-type nitride semiconductor layers;
forming a plurality of p-side nitride semiconductor layers on the plurality of the light absorption layers;
forming a p-side electrode electrically connected with the p-side nitride semiconductor layer; and
forming an n-side electrode electrically connected with the first n-type nitride semiconductor layer.
2. The method of claim 1 , wherein
the amorphous carbon layer has a thickness of not less than 20 nm and not more than 60 nm.
3. The method of claim 1 further comprising:
forming a buffer layer including a nitride semiconductor on the AlN layer.
4. The method of claim 2 further comprising:
forming a buffer layer including a nitride semiconductor on the AlN layer.
5. The method of claim 1 , wherein
the p-side electrode is a ZnO transparent conductive film.
6. The method of claim 4 , wherein
the p-side electrode is a ZnO transparent conductive film.
7. The method of claim 1 , wherein
each of the second n-type nitride semiconductor layers is columnar.
8. A solar cell comprising:
a graphite substrate;
an amorphous carbon layer formed on the graphite substrate;
an AlN layer formed on the amorphous carbon layer;
a first n-type nitride semiconductor layer formed on the AlN layer;
a plurality of second n-type nitride semiconductor layers formed on the first n-type nitride semiconductor layer, each of the second n-type nitride semiconductor layers being columnar;
a plurality of light absorption layers formed on the plurality of the second n-type nitride semiconductor layers;
a plurality of p-side nitride semiconductor layers formed on the plurality of the light absorption layers;
a p-side electrode connected electrically to the plurality of the p-type nitride semiconductor layers; and
an n-side electrode connected electrically to the first n-type nitride semiconductor layer.
9. The solar cell of claim 8 , wherein
the amorphous carbon layer has a thickness of not less than 20 nm and not more than 60 nm.
10. The solar cell of claim 8 , further comprising
a buffer layer includes a nitride semiconductor on the AlN layer.
11. The solar cell of claim 9 , further comprising
a buffer layer includes a nitride semiconductor on the AlN layer.
12. The solar cell of claim 8 , wherein
the p-side electrode is a ZnO transparent conductive film.
13. The solar cell of claim 11 , wherein
the p-side electrode is a ZnO transparent conductive film.