Doped perovskite having improved stability, and solar cells made thereof

1. A light-harvesting layer of a photovoltaic device, comprising: a perovskite absorber doped with a metal chalcogenide, wherein the perovskite absorber has the formula ABX 3 ,

A is selected from the group consisting of alkyl ammonium, formamidinium and mixtures thereof,

B is selected from the group consisting of lead, tin and mixtures thereof,

X is selected from the group consisting of F, Cl, Br, SCN, I and mixtures thereof, and

the metal of the metal chalcogenide is selected from the group consisting of lead, tin and mixtures thereof,

the chalcogenide of the metal chalcogenide is selected from the group consisting of S, Se, Te and mixtures thereof,

the light-harvesting layer is homogeneous, and

there is no phase separation between the metal chalcogenide and the perovskite absorber.

2. The light-harvesting layer of claim 1 , wherein

A is methyl ammonium,

B is the lead,

X is the I, and

The chalcogenide of the metal chalcogenide is the Se.

3. The light-harvesting layer of claim 1 , wherein the metal chalcogenide is present in an amount of 5 to 20 percent by weight.

4. A photovoltaic device, comprising:

(1) a first conductive layer,

(2) optionally an electron blocking layer, on the first conductive layer,

(3) a semiconductor layer, on the first conductive layer,

(4) the light-harvesting layer of claim 1 , on the semiconductor layer,

(5) a hole transport material, on the light-harvesting layer, and

(6) a second conductive layer, on the hole transport material.

5. The photovoltaic device of claim 4 , wherein

A is methyl ammonium,

B is the lead,

X is the I, and

The chalcogenide of the metal chalcogenide is the Se.

6. The photovoltaic device of claim 4 , wherein the metal chalcogenide is present in an amount of 5 to 20 percent by weight.

7. The photovoltaic device of claim 4 , wherein the first conductive layer is transparent.

8. The photovoltaic device of claim 4 , wherein the metal chalcogenide is present in an amount of 7 to 12 percent by weight.

9. The photovoltaic device of claim 4 , wherein the metal chalcogenide is present in an amount of 9 to 11 percent by weight.

10. The photovoltaic device of claim of claim 4 , further comprising the electron blocking layer.

11. The photovoltaic device of claim 4 , wherein the first conductive layer comprises at least one transparent conductor selected from the group consisting of indium-tin oxide, fluorinated tin oxide and aluminum-zinc oxide.

12. The light-harvesting material of claim 1 , wherein the metal chalcogenide is present in an amount of 7 to 12 percent by weight.

13. The light-harvesting material of claim 1 , wherein the metal chalcogenide is present in an amount of 9 to 11 percent by weight.

14. The light harvesting material of claim 2 , wherein the metal chalcogenide is present in an amount of 5 to 20 percent by weight.

15. The photovoltaic device of claim 5 , wherein the metal chalcogenide is present in an amount of 5 to 20 percent by weight.

16. The photovoltaic device of claim 5 , wherein the first conductive layer comprises at least one transparent conductor selected from the group consisting of indium-tin oxide, fluorinated tin oxide and aluminum-zinc oxide.

17. The photovoltaic device of claim 4 , wherein the hole-transporting material is selected from the group consisting of Cul, CuSCN, CuAlO 2 , NiO and mixtures thereof.

18. The photovoltaic device of claim 4 , wherein the semi-conductor is selected from the group consisting of titanium dioxide (TiO 2 ), zinc oxide (ZnO), zirconium oxide (ZrO 2 ), tungsten oxide (WO 3 ), molybdenum oxide (MoO 3 ), lead oxide (PbO) and mixtures thereof.

19. The photovoltaic device of claim 4 , wherein the second conductive layer is selected from the group consisting of gold, platinum, nickel, metallic alloys and mixtures thereof.

20. The photovoltaic device of claim 5 , wherein the first conductive layer comprises at least one transparent conductor selected from the group consisting of indium-tin oxide, fluorinated tin oxide and aluminum-zinc oxide,

the hole-transporting material is selected from the group consting of Cul, CuSCN, CuAlO 2 , NiO and mixtures thereof,

the semi-conductor is selected from the group consisting of titanium dioxide (TiO 2 ), zinc oxide (ZnO), zirconium oxide (ZrO 2 ), tungsten oxide (WO 3 ), molybdenum oxide (MoO 3 ), lead oxide (PbO) and mixtures thereof, and

the second conductive layer is selected from the group consisting of gold, platinum, nickel, metallic alloys and mixtures thereof.