Sulfur salt containing CIG targets, methods of making and methods of use thereof

1. A method of making a photovoltaic device, comprising:

forming a compound semiconductor layer comprising copper, indium, gallium, selenium and sulfur by reactive sputtering at least one target comprising copper, indium, gallium and a sulfur compound in an atmosphere comprising selenium.

2. The method of claim 1 , wherein the compound semiconductor layer is a p-type copper indium gallium sulfur selenide absorber layer.

3. The method of claim 2 , further comprising:

forming a first electrode below the p-type copper indium gallium sulfur selenide absorber layer;

forming an n-type window semiconductor layer over the p-type copper indium gallium sulfur selenide absorber layer; and

forming a transparent electrode over the n-type window semiconductor layer.

4. The method of claim 3 , wherein a p-n junction is formed between the n-type window semiconductor layer and the p-type copper indium gallium sulfur selenide absorber layer.

5. The method of claim 3 , further comprising:

moving a web substrate though a plurality of sputtering chambers; and

forming the compound semiconductor layer in a first chamber of the plurality of chambers by reactive sputtering the p-type copper indium gallium sulfur selenide absorber layer from the at least one target in an evaporated selenium containing atmosphere.

6. The method of claim 5 , wherein forming the n-type window semiconductor layer comprises sputtering an n-type copper indium sulfur selenide layer or a copper indium sulfide layer by reactive or non-reactive sputtering.

7. The method of claim 1 , wherein the compound semiconductor layer further comprises sodium.

8. The method of claim 7 , wherein the sulfur and the sodium are located in the same at least one target.

9. The method of claim 8 , wherein the sulfur compound and the sodium comprise the same Na 2 S or Na 2 SO 3 compound in the at least one target.

10. The method of claim 8 , wherein the sulfur compound and the sodium do not comprise the same compound in the at least one target.

11. The method of claim 10 , wherein the sulfur compound comprises CuS, Cu 2 S, GaS, In 2 S 3 , Se 2 S 6 , S 7 NH, or N 4 S 3 F 3 compound.

12. The method of claim 10 , wherein the sulfur compound comprises GaS, Se 2 S 6 , S 7 NH, or N 4 S 3 F 3 compound.

13. The target of claim 1 , wherein the target excludes selenium.

14. A sputtering target comprising indium and a sulfur compound, the bulk of the target essentially excluding selenium; and

wherein the sputtering target has a sulfur concentration in a range of 5 to 40 at %,

wherein the target comprises a copper-indium-gallium alloy which contains the sulfur compound or a copper indium alloy which contains the sulfur compound.

15. The target of claim 14 , wherein the sulfur compound comprises CuS, Cu 2 S, Na 2 S, Na 2 SO 3 , GaS, In 2 S 3 , Se 2 S 6 , S 7 NH, or N 4 S 3 F 3 .

16. The target of claim 14 , wherein the sputtering target has a sulfur concentration of 5-15 at %.

17. The target of claim 14 , wherein the target excludes sodium.

18. The target of claim 14 , wherein the sulfur compound comprises GaS, Se 2 S 6 , S 7 NH, or N 4 S 3 F 3 compound.

19. The target of claim 14 , wherein the bulk of the target completely excludes selenium.

20. A method of making a sputtering target comprising:

combining an indium containing material and a sulfur containing compound to form a combined sputtering material, the combined sputtering material essentially excluding selenium, wherein the combined sputtering material has a sulfur concentration in a range of 5 to 40 at %; and

providing the combined sputtering material onto a target support to form an indium and sulfur compound containing target,

wherein the indium containing material comprises a copper-indium-gallium alloy which contains the sulfur containing compound or a copper-indium alloy which contains the sulfur compound.

21. The method of claim 20 , wherein the sulfur containing compound comprises CuS, Cu 2 S, Na 2 S, Na 2 SO 3 , GaS, In 2 S 3 , Se 2 S 6 , S 7 NH, or N 4 S 3 F 3 .

22. The method of claim 20 , wherein the step of combining comprises combining a copper-indium-gallium or copper-indium powder and a sulfur containing compound powder.

23. The method of claim 22 , wherein the powders are combined under an inert atmosphere and wherein the step of providing comprises pressing a powder of the combined sputtering material onto the target support.

24. The method of claim 20 , wherein the step of combining comprises:

combining a copper-indium-gallium or copper-indium powder with sulfur compound containing solution; and

evaporating a solvent from the solution.

25. The method of claim 24 , wherein the solvent is water and the step of evaporating comprises performing a dehydration heat treatment.

26. The method claim 20 , wherein:

the step of combining comprises combining a copper, indium and gallium containing melt with the sulfur containing compound to form a liquid of the combined sputtering material; and

the step of providing comprises casting or spraying the liquid onto the target support.

27. The method of claim 20 , wherein the sulfur containing compound comprises GaS, Se 2 S 6 , S 7 NH, or N 4 S 3 F 3 compound.

28. The method of claim 20 , wherein the combined sputtering material completely excludes selenium.

29. A sputtering target comprising indium and a sulfur compound, the bulk of the target essentially excluding selenium; and

wherein the sputtering target has a sulfur concentration of 5-15 at %.

30. The target of claim 29 , wherein the target further comprises at least one of copper and gallium.