Solar cell and method for manufacturing same

1. A solar cell comprising:

a support substrate;

a barrier layer on the support substrate; and

a photo-electro conversion part on the barrier layer,

wherein the barrier layer comprises first and second barrier layers having porosities different from each other;

wherein the support substrate includes a flexible metallic substrate;

wherein the photo-electro conversion part includes a first electrode layer, a light absorbing layer, and a second electrode layer;

wherein the first and second barrier layers are in direct physical contact with each other;

wherein the second barrier layer is in direct physical contact with the first electrode layer;

wherein the first electrode layer includes at least one of molybdenum (Mo), copper (Cu), nickel (Ni), aluminum, and an alloy thereof;

wherein the porosity of the second barrier layer is higher than the porosity of the first barrier layer; and

wherein the porosity of the second barrier layer is in a range of 20% to 40%.

2. The solar cell of claim 1 , further comprising a metallic layer on the support substrate.

3. The solar cell of claim 1 , wherein the first barrier layer is provided on the support substrate, and

the second barrier layer is provided on the first barrier layer.

4. The solar cell of claim 1 , wherein the porosity of the first barrier layer is 10%.

5. The solar cell of claim 1 , wherein the first and second barrier layers include a same material.

6. The solar cell of claim 1 , wherein a ratio of a thickness of the second barrier layer to a thickness of the first barrier layer is in a range of 0.1 to 0.3.

7. The solar cell of claim 1 , wherein the barrier layer has a thickness of 5 μm or less.

8. The solar cell of claim 1 , wherein the barrier layer includes oxide.

9. The solar cell of claim 8 , wherein the barrier layer includes at least one selected from the group consisting of aluminum oxide, titanium oxide, magnesium oxide, tungsten oxide, and a combination thereof.

10. The solar cell of claim 1 ,

wherein the first electrode layer is on the barrier layer,

wherein the light absorbing layer is on the first electrode layer,

wherein the second electrode layer is on the light absorbing layer, and

wherein the second electrode layer includes a transparent conductive material.