Multi-junction solar cell devices

1. A photovoltaic cell structure for manufacturing a photovoltaic device, the photovoltaic cell structure comprises:

a substrate including a surface region;

a first conductor layer overlying the surface region;

a lower cell structure, the lower cell structure comprising

a first P type absorber comprising at least a first metal chalcogenide material and/or other suitable semiconductor material overlying the first conductor layer, the first P type absorber material being characterized by a first bandgap ranging from 0.5 eV to 1.0 eV, a first optical absorption coefficient greater than about 10 4 cm −1 , and a first thickness ranging from 0.5 μm to 2 μm;

a first N+ type window layer comprising at least a second metal chalcogenide material and/or other suitable semiconductor material overlying the first P type absorber layer;

an upper cell structure, the upper cell structure comprising:

a second P type absorber material comprising at least a third metal chalcogenide material, the second P type absorber material being characterized by a second bandgap ranging from 1.0 eV to 2.2 eV and a second optical absorption coefficient greater than about 10 4 cm −1 , a second thickness ranging from 0.5 μm to 2 μm, wherein the second P type absorber material comprises a copper oxide material;

a second N+ type window layer comprising at least a fourth metal chalcogenide material overlying the second absorber layer, wherein the fourth metal chalcogenide comprises zinc sulfide;

a buffer layer overlying the second N+ type window layer of the upper cell structure; the buffer layer being characterized by a resistivity greater than about 10 kohm-cm; and

a second conductor layer overlying the buffer layer; and

an adhesion layer disposed between the first N+ type window layer and the second P type absorber material.

2. The photovoltaic cell structure of claim 1 wherein the substrate is a semiconductor or a compound semiconductor material.

3. The photovoltaic cell structure of claim 1 wherein the first metal chalcogenide material is selected from a semiconductor metal oxide, a semiconductor metal sulfide, a semiconductor metal selenide, or semiconductor metal telluride.

4. The photovoltaic cell structure of claim 1 wherein the second metal chalcogenide material is selected from a semiconductor metal oxide, a semiconductor metal sulfide, a semiconductor metal selenide, or a semiconductor metal telluride, or a semiconductor metal silicide.

5. The photovoltaic cell structure of claim 1 wherein the first P type absorber layer comprises an iron disilicide material.

6. The photovoltaic cell structure of claim 1 wherein the first N+ type window layer comprises a zinc sulfide material.

7. The photovoltaic cell structure of claim 1 wherein the second N+ window layer comprises a zinc sulfide material.

8. The photovoltaic cell structure of claim 1 wherein the first bandgap is less than the second bandgap.

9. The photovoltaic cell structure of claim 1 wherein the first conductor layer comprises a transparent conducting oxide material selected from ZnO:Al, SnO:F, or ITO.

10. The photovoltaic cell structure of claim 1 wherein the second conductor layer comprises a transparent conducting oxide material selected from ZnO:Al, SnO:F, or ITO.

11. The photovoltaic cell structure of claim 1 wherein the adhesion layer comprises ethyl vinyl acetate or polyvinyl butyral.

12. The photovoltaic cell structure of claim 1 , wherein the buffer comprises intrinsic zinc sulfide.