PHOTOVOLTAIC DEVICE

1 . A photovoltaic device, comprising:

a first semiconductor layer;

a p+-type semiconductor layer; and

an interlayer interposed between the first semiconductor layer and the p+-type semiconductor layer, wherein the interlayer comprises magnesium and tellurium.

2 . The photovoltaic device of claim 1 , wherein the interlayer comprises a composition having a formula (I):

(I) Mg x Cd a-x Te;

wherein “x” is in a range from about 0.05 to about 0.6.

3 . The photovoltaic device of claim 2 , wherein “x” is in a range from about 0.1 to about 0.3.

4 . The photovoltaic device of claim 1 , wherein a percentage difference between a lattice constant of the first semiconductor layer and a lattice constant of the interlayer is less than about 1%.

5 . The photovoltaic device of claim 1 , wherein the interlayer has a band gap in a range from about 1.5 eV to about 3.5 eV.

6 . The photovoltaic device of claim 1 , wherein the interlayer has a band gap in a range from about 1.5 eV to about 2.5 eV.

7 . The photovoltaic device of claim 1 , wherein the interlayer comprises a p-doped magnesium telluride or a p-doped magnesium cadmium telluride.

8 . The photovoltaic device of claim 1 , wherein the first semiconductor layer comprises a p-type material.

9 . The photovoltaic device of claim 1 , wherein the first semiconductor layer comprises a substantially intrinsic material.

10 . The photovoltaic device of claim 1 , wherein the first semiconductor layer comprises a material selected from a group consisting of cadmium telluride, cadmium zinc telluride, cadmium sulfur telluride, cadmium manganese telluride, cadmium magnesium telluride, and combinations thereof.

11 . The photovoltaic device of claim 1 , wherein the first semiconductor layer has a band gap in a range from about 1.3 eV to about 1.6 eV.

12 . The photovoltaic device of claim 1 , wherein the p+-type semiconductor layer comprises a p-type material selected from a group consisting of amorphous Si:H, amorphous SiC:H, crystalline Si, microcrystalline Si:H, microcrystalline SiGe:H, amorphous SiGe:H, amorphous Ge, microcrystalline Ge, GaAs, BaCuSF, BaCuSeF, BaCuTeF, LaCuOS, LaCuOSe, LaCuOTe, (LaSr)CuOS, LaCuOSe 0.6 Te 0.4 , BiCuOSe, (BiCa)CuOSe, PrCuOSe, NdCuOS, Sr 2 Cu 2 ZnO 2 S 2 , Sr 2 CuGaO 3 S, and combinations thereof.

13 . The photovoltaic device of claim 1 , wherein the p+-type semiconductor layer comprises a p+doped material selected from a group consisting of zinc telluride, magnesium telluride, manganese telluride, beryllium telluride, mercury telluride, arsenic telluride, antimony telluride, copper telluride, and combinations thereof.

14 . The photovoltaic device of claim 13 , wherein the p+doped material further comprises a dopant selected from a group consisting of copper, gold, nitrogen, phosphorus, antimony, arsenic, silver, bismuth, sulfur, sodium, and combinations thereof.

15 . The photovoltaic device of claim 1 , wherein the p+-type semiconductor layer has a carrier density in a range from about 10 17 per cubic centimeter to about 10 20 per cubic centimeter.

16 . The photovoltaic device of claim 1 , wherein the first semiconductor layer has a thickness in a range from about 1 micron to about 3 microns.

17 . The photovoltaic device of claim 1 , wherein the p+-type semiconductor layer has a thickness in a range from about 50 nm to about 200 nm.

18 . The photovoltaic device of claim 1 , wherein the interlayer has a thickness in a range from about 10 nm to about 100 nm.

19 . The photovoltaic device of claim 1 , further comprising a first electrically conductive layer disposed on the p+-type semiconductor layer.

20 . The photovoltaic device of claim 19 , wherein the first electrically conductive layer comprises gold, platinum, molybdenum, aluminum, chromium, nickel, or silver.

21 . The photovoltaic device of claim 1 , further comprising a second semiconductor layer, wherein the first semiconductor layer is disposed on the second semiconductor layer.

22 . The photovoltaic device of claim 21 , wherein the second semiconductor layer comprises an n-type material.

23 . The photovoltaic device of claim 21 , wherein the second semiconductor layer comprises cadmium sulfide, cadmium selenide, oxygenated cadmium sulfide, zinc telluride, zinc selenide, zinc sulfide, indium selenide, indium sulfide, zinc oxihydrate, or combinations thereof.

24 . The photovoltaic device of claim 21 , further comprising a second electrically conductive material, wherein the second semiconductor layer is disposed on the second electrically conductive layer.

25 . The photovoltaic device of claim 24 , wherein the second electrically conductive layer comprises cadmium tin oxide, indium tin oxide, zinc tin oxide, fluorine-doped tin oxide, indium-doped cadmium oxide, aluminum-doped zinc oxide, indium zinc oxide, or combinations thereof.

26 . A photovoltaic device, comprising:

a support;

a second electrically conductive layer disposed on the support;

an n-type semiconductor layer disposed on the second electrically conductive layer;

a substantially intrinsic semiconductor layer disposed on the n-type semiconductor layer;

a p+-type semiconductor layer disposed on the substantially intrinsic semiconductor layer;

a first electrically conductive layer disposed on the p+-type semiconductor layer; and

an interlayer interposed between the p+-type semiconductor layer and the substantially intrinsic semiconductor layer, wherein the interlayer comprises magnesium and tellurium.

27 . A photovoltaic module comprising a plurality of photovoltaic devices as defined in claim 26 .