Solar cell

1. A solar cell comprising:

a semiconductor substrate being of an n-type conductive;

a first passivation layer on one surface of the semiconductor substrate;

a first conductive area disposed on the first passivation layer, the first conductive area being of a p-type conductive;

a second conductive area of the n-type conductive disposed on the first passivation layer;

a second passivation layer covering the first conductive area and the second conductive area;

a first electrode connected to the first conductive area; and

a second electrode connected to the second conductive area,

wherein the second conductive area is formed of a metal compound layer comprising indium, gallium, and zinc,

wherein, in the second conductive area, an amount of indium is greater than each of an amount of gallium, an amount of zinc, and an amount of oxygen, and

wherein the first passivation layer is formed on the entire one surface of the semiconductor substrate.

2. The solar cell according to claim 1 , wherein both the first conductive area and the second conductive area are disposed on the first passivation layer.

3. The solar cell according to claim 2 , wherein at least one of the first conductive area and the second conductive area does not include a semiconductor material and a material serving as a dopant in the semiconductor material.

4. The solar cell according to claim 2 , wherein the first conductive area includes an emitter area having a metal compound layer selectively collecting holes, and

wherein the first conductive area has a lower Fermi level than a Fermi level of the semiconductor substrate and a greater work function than a work function of the semiconductor substrate, or the first conductive area is formed of a molybdenum oxide layer, a tungsten oxide layer, or a vanadium oxide layer.

5. The solar cell according to claim 2 , wherein the second conductive area includes a field area having the metal compound layer selectively collecting electrons, and

wherein the second conductive area has a higher Fermi level than a Fermi level of the semiconductor substrate and a smaller work function than a work function of the semiconductor substrate, or the second conductive area is formed of a titanium oxide layer or a zinc oxide layer.

6. The solar cell according to claim 2 , wherein the first conductive area is formed of a first metal compound layer, and

wherein the second conductive area is formed of a second metal compound layer, which is different from the first metal compound layer.

7. The solar cell according to claim 2 , wherein the first electrode or the second electrode, connected to at least one of the first conductive area and the second conductive area, includes a first electrode layer comprising a transparent conductive material, and a second electrode layer formed on the first electrode layer, the second electrode layer having a pattern and comprising a metal material.

8. The solar cell according to claim 2 , further comprising a front surface field forming layer disposed on an opposite surface of the semiconductor substrate, the front surface field forming layer having a fixed charge, or being a layer formed of a metal compound,

wherein the front surface field forming layer includes at least one of an aluminum oxide layer, a molybdenum oxide layer, a tungsten oxide layer, a vanadium oxide layer, a titanium oxide layer, and a zinc oxide layer.

9. The solar cell according to claim 2 , further comprising a front surface field forming layer disposed on an opposite surface of the semiconductor substrate, the front surface field forming layer having a fixed charge, or being a layer formed of a metal compound,

wherein the layer formed of the metal compound, which constitutes the front surface field forming layer, and the metal compound layer, which constitutes at least one of the first conductive area and the second conductive area, are formed of the same material.

10. The solar cell according to claim 1 , wherein the first conductive area comprises a semiconductor material different from a semiconductor material of the second conductive area.

11. The solar cell according to claim 10 , wherein the first conductive area comprises a single semiconductor material.

12. The solar cell according to claim 1 , wherein the amount of zinc is greater than each of the amount of gallium and the amount of oxygen.

13. The solar cell according to claim 1 , wherein the semiconductor substrate comprises a single semiconductor material, and the semiconductor material of the semiconductor substrate is different from the semiconductor material of the second conductive area, and

wherein the semiconductor substrate and the first conductive area comprise the same single semiconductor material, but have different crystalline structures.

14. The solar cell according to claim 10 , wherein the first conductive area forms an emitter area, and

wherein the second conductive area forms a front surface field area or a back surface field area.

15. The solar cell according to claim 10 , wherein a separator area or a barrier area is located between the first conductive area and the second conductive area.

16. The solar cell according to claim 10 , wherein the second conductive area is disposed on an opposite surface of the semiconductor substrate, and

wherein the second conductive area is in contact with the semiconductor substrate, or another passivation layer is further located between the semiconductor substrate and the second conductive area.

17. The solar cell according to claim 1 , wherein the one surface of the semiconductor substrate is a back surface of the semiconductor substrate.

18. The solar cell according to claim 1 ,

wherein a work function of the second conductive area is within a range from about 4.60 Ev to about 4.85 Ev.

19. The solar cell according to claim 18 , wherein a portion of the second passivation layer extends between the first conductive area and the second conductive area, and contacts the first passivation layer.