Solar cell and method for manufacturing the same, and method for forming impurity region

1. A method for manufacturing a solar cell, the method comprising:

forming an impurity layer on a substrate of a first conductive type, the impurity layer having impurities of a second conductive type opposite the first conductive type;

forming a first emitter portion having a first impurity concentration in the substrate using the impurity layer by heating the substrate with the impurity layer to diffuse the impurities into the substrate;

forming a second emitter portion having a second impurity concentration at the first emitter portion using the impurity layer by irradiating laser beams on a region of the impurity layer to diffuse the impurities into the substrate, the second impurity concentration being greater than the first impurity concentration; and

forming a first electrode connected to the second emitter portion and a second electrode connected to the substrate.

2. The method of claim 1 , wherein an impurity doped depth of the second emitter portion is different from an impurity doped depth of the first emitter portion.

3. The method of claim 1 , wherein the second emitter portion is a line type.

4. The method of claim 1 , wherein the second emitter portion is a dot type.

5. The method of claim 1 , wherein the forming of the impurity layer forms the impurity layer by using a screen printing method.

6. The method of claim 1 , wherein the forming of the impurity layer forms the impurity layer by using a sputtering method, an ink jetting method, a spin-on coating method, or a spraying method.

7. The method of claim 1 , wherein the impurity layer is formed on an entire surface of the substrate.

8. The method of claim 1 , wherein the impurity layer is formed on a portion of the substrate.

9. The method of claim 1 , further comprising removing the impurity layer after the forming of the second emitter portion.

10. A method for manufacturing a solar cell, the method comprising:

forming a first impurity layer and a second impurity layer on a substrate of a first conductive type, the first impurity layer containing impurities of a second conductive type opposite the first conductive type and the second impurity layer containing impurities of the first conductive type;

forming a first impurity portion in a portion of the substrate on which the first impurity layer is formed and a second impurity portion in a portion of the substrate on which the second impurity layer is formed, by heating the substrate to diffuse the respective impurities into the substrate;

forming a first high-doped impurity portion at the first impurity portion and having an impurity concentration higher than an impurity concentration of the first impurity portion by irradiating laser beams on a portion of the first impurity layer and a second high-doped impurity portion at the second impurity portion and having an impurity concentration higher than an impurity concentration of the second impurity portion by irradiating laser beams on a portion of the second impurity layer to diffuse the respective impurities into the substrate; and

forming a first electrode connected to the first high-doped impurity portion and a second electrode connected to the second high-doped impurity portion.

11. The method of claim 10 , wherein the first impurity portion and the second impurity portion are simultaneously formed.

12. The method of claim 10 , wherein the first high-doped impurity portion and the second high-doped impurity portion are simultaneously formed.