Solar cell and method of manufacturing the same
Disclosed is a method of manufacturing a solar cell, the method including forming a tunneling layer over one surface of a semiconductor substrate, forming a semiconductor layer over the tunneling layer, forming a conductive area including a first conductive area of a first conductive type and a second conductive area of a second conductive type in the semiconductor layer, and forming an electrode including a first electrode connected to the first conductive area and a second electrode connected to the second conductive area. The forming of the conductive area includes forming a mask layer over the semiconductor layer, forming a doping opening corresponding to at least one of the first conductive area and the second conductive area in the mask layer using a laser, and performing doping using the doping opening.
1. A method of manufacturing a solar cell, the method comprising:
forming a tunneling layer over one surface of a semiconductor substrate;
forming a semiconductor layer over the tunneling layer;
forming a conductive area including a first conductive area of a first conductive type and a second conductive area of a second conductive type in the semiconductor layer; and
forming an electrode including a first electrode connected to the first conductive area and a second electrode connected to the second conductive area,
wherein the forming of the conductive area includes:
forming a mask layer over the semiconductor layer;
forming a doping opening corresponding to at least one of the first conductive area and the second conductive area in the mask layer using a laser; and
performing doping using the doping opening,
wherein a mark is made in the semiconductor layer in the forming of the doping opening.
2. The method according to claim 1 ,
wherein the mark includes an outer mark formed along a longitudinally extending edge of at least one of the first conductive area and the second conductive area.
3. The method according to claim 2 , wherein the outer mark takes a form of a line formed along each of opposite longitudinally extending edges of at least one of the first conductive area and the second conductive area.
4. The method according to claim 2 , wherein the mark is not formed inside at least one of the first conductive area and the second conductive area.
5. The method according to claim 2 , wherein the mark further includes an inner mark formed inside at least one of the first conductive area and the second conductive area.
6. The method according to claim 5 , wherein the outer mark is denser than the inner mark in at least one of the first conductive area and the second conductive area.
7. The method according to claim 5 , wherein the inner mark has a line shape, a closed curve shape, or a polygonal shape, which crosses the outer mark.
8. The method according to claim 1 , wherein the first conductive area is of a different conductive type from that of a base area of the semiconductor substrate,
wherein the second conductive area is of the same conductive type as that of the base area of the semiconductor substrate, and
wherein the mark is formed at an edge of the second conductive area and is not formed in the first conductive area.
9. The method according to claim 1 , wherein each of the first conductive area and the second conductive area has a stripe arrangement, and
wherein, in the forming of the doping opening, laser beams of the laser are emitted so as to overlap each other in a longitudinal direction of at least one of the first conductive area and the second conductive area, thereby forming the doping opening.
10. The method according to claim 1 , wherein the forming of the conductive area further includes forming a first doping layer, which includes an opening and corresponds to an area on which the first conductive area is to be formed, between the forming of the semiconductor layer and the forming of the mask layer,
wherein, in the forming of the mask layer, the mask layer is formed over the entire semiconductor layer and the entire first doping layer,
wherein, in the forming of the doping opening, the doping opening is formed so as to correspond to the second conductive area, and
wherein, in the performing of the doping, a first conductive dopant, included in the first doping layer, is diffused to the semiconductor layer via thermal treatment in a gas atmosphere, which includes a second conductive dopant, so as to form the first conductive area, and the second conductive dopant is diffused to the semiconductor layer so as to form the second conductive area.
11. The method according to claim 10 , wherein, in the forming of the doping opening, the doping opening is formed to have a smaller area than that of the opening of the first doping layer, so that an undoped barrier area is located between the first conductive area and the second conductive area after the performing of the doping, and
wherein, in the performing of the doping, an opposite surface of the semiconductor substrate is doped with the second conductive dopant so that a front surface field area is formed on the opposite surface of the semiconductor substrate.