Solar cell and method for manufacturing the same

1. A solar cell comprising:

a substrate formed of an n-type crystalline semiconductor;

an emitter region of a p-type positioned at a first surface of the substrate;

an anti-reflection layer positioned on the first surface of the substrate;

a passivation layer positioned on a second surface which is opposite of the first surface of the substrate;

a first electrode which is positioned on the first surface of the substrate and is connected to the emitter region; and

a second electrode which is positioned on the second surface of the substrate and is connected to the substrate,

wherein the anti-reflection layer includes a first anti-reflection layer formed of aluminum oxide,

a second anti-reflection layer which is positioned directly on the first anti-reflection layer and is formed of hydrogenated silicon nitride, and

a third anti-reflection layer which is positioned directly on the second anti-reflection layer and is formed of hydrogenated silicon oxide,

wherein the passivation layer includes a first passivation layer formed of hydrogenated silicon nitride,

a second passivation layer which is positioned directly on the first passivation layer and is foamed of hydrogenated silicon oxide, and

a third passivation layer which is positioned directly on the second passivation layer and is formed of aluminum oxide,

wherein the emitter region has a first textured surface including a plurality of first protrusions each having a protruding height and a maximum diameter which are within a range of about 5 μm to 10 μm, and

wherein each of the plurality of first protrusions has a second textured surface including a plurality of second protrusions each having a protruding height and a maximum diameter which are within a range of about 300 nm to 600 nm.

2. The solar cell of claim 1 , wherein the first anti-reflection layer has a thickness of about 5 nm to 15 nm.

3. The solar cell of claim 2 , wherein each of the second anti-reflection layer and the first passivation layer has a thickness of about 70 nm to 100 nm.

4. The solar cell of claim 1 , wherein the second passivation layer has a thickness of about 50 nm to 100 nm.

5. The solar cell of claim 1 , further comprising a silicon oxide layer positioned between the second surface of the substrate and the first passivation layer.

6. The solar cell of claim 5 , wherein the silicon oxide layer has a thickness of about 2 nm to 3 nm.

7. The solar cell of claim 1 , wherein the first surface and the second surface of the substrate are incident surfaces on which light is incident.

8. The solar cell of claim 1 , wherein the hydrogenated silicon oxide of the third anti-reflective layer and the second passivation layer each has a thickness of about 50 nm to 100 nm.

9. The solar cell of claim 1 , further comprising a silicon oxide layer positioned between the emitter region and the first anti-reflection layer.

10. The solar cell of claim 9 , wherein the silicon oxide layer has a thickness of about 2 nm to 3 nm.

11. The solar cell of claim 1 , wherein acicular ends of the plurality of second protrusions point in a parallel direction as vertices of the plurality of first protrusions.

12. The solar cell of claim 1 , wherein the first and second textured surfaces are also formed on the second surface of the substrate.

13. The solar cell of claim 1 , wherein each of the plurality of second protrusions has an acicular end, and acicular ends of adjacent second protrusions are connected by serrated edges.