Heterojunction III-V solar cell performance
An In x Ga 1-x As interlayer is provided between a III-V base and an intrinsic amorphous semiconductor layer of a heterojunction III-V solar cell structure. Improved surface passivation and open circuit voltage may be obtained through the incorporation of the interlayer within the structure.
1. A heterojunction III-V solar cell structure comprising:
a base layer comprising In y Ga 1-y As;
an intrinsic semiconductor layer;
an epitaxial In x Ga 1-x As interlayer between and interfacing with the base layer and the intrinsic semiconductor layer, wherein 0.01<x<1.0 and 0<y<x;
the base layer and the interlayer having the same doping type;
a doped hydrogenated amorphous silicon layer on the intrinsic semiconductor layer;
and a transparent conductive layer on the doped hydrogenated amorphous silicon layer.
2. The heterojunction III-V solar cell structure of claim 1 , wherein 0.05≦x≦0.8.
3. The heterojunction III-V solar cell structure of claim 1 , wherein the intrinsic semiconductor layer comprises intrinsic hydrogenated amorphous silicon, and wherein the intrinsic hydrogenated amorphous silicon includes germanium and carbon atoms.
4. The heterojunction III-V solar cell structure of claim 1 , wherein the In x Ga 1-x As interlayer has a thickness between 5-50 nm.
5. The heterojunction III-V solar cell structure of claim 1 , wherein the hydrogenated amorphous silicon layer has a doping type opposite to the doping type of the base layer.
6. A heterojunction III-V solar cell structure, comprising:
a base layer comprising gallium arsenide;
an intrinsic semiconductor layer comprising hydrogenated amorphous silicon;
an epitaxial In x Ga 1-x As interlayer between and interfacing with the base layer and the intrinsic semiconductor layer, wherein 0.01<x<1.0;
a doped hydrogenated amorphous silicon layer on the intrinsic semiconductor layer, and
a transparent conductive layer above the hydrogenated amorphous silicon layer,
the base layer and the In x Ga 1-x As interlayer having a first doping type, the doped hydrogenated amorphous silicon layer having a second doping type opposite from the first doping type.
7. The heterojunction III-V solar cell structure of claim 6 , wherein 0.05≦x≦0.8.
8. The heterojunction III-V solar cell structure of claim 6 , wherein the In x Ga 1-x As interlayer has a thickness between 5-50 nm.
9. A heterojunction III-V solar cell structure, comprising: an intrinsic semiconductor layer comprising hydrogenated amorphous silicon; an epitaxial In x Ga 1-x As interlayer; a base layer comprising one of GaAs and In y Ga 1-y As where 0<y<x; the epitaxial In x Ga 1-x As interlayer being between and interfacing with the base layer and the intrinsic semiconductor layer, wherein 0.05<x<0.8; the base layer and the In x Ga 1-x As interlayer having the same doping type; a doped hydrogenated amorphous silicon layer on the intrinsic semiconductor layer, and a transparent conductive layer on the doped hydrogenated amorphous silicon layer.
10. A heterojunction III-V solar cell structure, comprising: an intrinsic semiconductor layer comprising a plurality of hydrogenated amorphous silicon layers; an epitaxial In x Ga 1-x As interlayer; a base layer comprising one of GaAs and In y Ga 1-y As where 0<y<x; the epitaxial In x Ga 1-x As interlayer being between and interfacing with the base layer and the intrinsic semiconductor layer, wherein 0.05<x<0.8; the base layer and the In x Ga 1-x As interlayer having the same doping type; a doped hydrogenated amorphous silicon layer on the intrinsic semiconductor layer, and a transparent conductive layer on the doped hydrogenated amorphous silicon layer.
11. A heterojunction III-V solar cell structure, comprising:
a base layer comprising GaAs;
an intrinsic semiconductor layer comprising hydrogenated amorphous silicon;
an epitaxial In x Ga 1-x As interlayer between and interfacing with the base layer and the intrinsic semiconductor layer, wherein 0.01<x<1.0, the base layer and the In x Ga 1-x As interlayer having the same doping type;
a doped hydrogenated amorphous silicon layer on the intrinsic semiconductor layer, and
a transparent conductive layer on the doped hydrogenated amorphous silicon layer.
12. A method comprising: obtaining a base layer comprising In y Ga 1-y As;
forming an intrinsic semiconductor layer;
forming an epitaxial In x Ga 1-x As interlayer between and interfacing with the base layer and the intrinsic semiconductor layer, wherein 0.01<x<1.0 and 0<y<x;
the base layer and the interlayer having the same doping type;
forming a doped hydrogenated amorphous silicon layer on the intrinsic semiconductor layer;
and forming a transparent conductive layer on the doped hydrogenated amorphous silicon layer.
13. The method of claim 12 , wherein 0.05<x<0.8.
14. The method of claim 12 , wherein the intrinsic semiconductor layer comprises intrinsic hydrogenated amorphous silicon.
15. The method of claim 14 , wherein the intrinsic hydrogenated amorphous silicon further includes germanium and carbon atoms.
16. The method of claim 14 , wherein 0.05<x<0.8.