Selective emitter solar cell
View Patent ↗A manufacturing method of selective emitter solar cell can include, forming an emitter layer positioned on a light receiving surface of the substrate having a first conductive type, the emitter layer having a second conductive type opposite to the first conductive type, forming a first emitter portion having a first impurity concentration and a second emitter portion having a second impurity concentration higher than the first impurity concentration on the emitter layer using a etch stop mask or a mask pattern, and forming a plurality of first electrodes connected to the second emitter portion, wherein the second emitter portion includes a first region that contacts the first electrodes and overlaps the first electrodes and a second region that is positioned around the first region and does not overlap the first electrodes, and the line width of the second region is more than the line width of each first electrode and less than four times the line width of each first electrode.
1. A manufacturing method of a selective emitter solar cell, the method comprising:
forming an emitter layer positioned on a light receiving surface of a substrate having a first conductive type, the emitter layer having a second conductive type opposite to the first conductive type at a first impurity concentration;
forming a high concentration emitter portion having a second impurity concentration higher than the first impurity concentration on the emitter layer; and
forming a plurality of first electrodes and a current collector connected to the high concentration emitter portion after forming a selective emitter structure having the emitter layer and the high concentration emitter portion, each of the plurality of first electrodes having a first line width (W 2 ) and the current collector having a second line width (W 1 ) greater than the first line width,
wherein the high concentration emitter portion includes;
a first contact portion having the first line width (W 2 ), and which is in contact with the plurality of first electrodes;
a first non-contact portion having a third line width (W 3 ), and which is positioned around the first contact portion and is not in contact with the plurality of first electrodes;
a second contact portion having the second line width (W 1 ), and which is in contact with the current collector; and
a second non-contact portion having a fourth line width (W 4 ), and which is positioned around the second contact portion and is not in contact with the current collector,
wherein the third line width (W 3 ) is equal to or greater than the first line width (W 2 ) and less than or equal to eight times the first line width (W 2 ), and
wherein the fourth line width (W 4 ) is greater than the second line width (W 1 ) and less than or equal to 1.4 times the second line width (W 1 ).
2. The manufacturing method of a selective emitter solar cell of claim 1 , wherein the first line width (W 2 ) of each first electrode is 40 μm to 100 μm.
3. The manufacturing method of a selective emitter solar cell of claim 1 , wherein the forming of the emitter layer and the high concentration emitter portion includes:
forming an etch stop mask on a portion of the emitter layer to form the high concentration emitter portion;
etching the emitter layer in a state that the etch stop mask is partially positioned on the emitter layer; and
removing the etch stop mask.
4. The manufacturing method of a selective emitter solar cell of claim 3 , wherein in the etching of the emitter layer, another portion of the emitter layer on which the etch stop mask is not positioned, is etched to a predetermined thickness.
5. The manufacturing method of a selective emitter solar cell of claim 4 , wherein by the etching of the emitter layer,
the portion of the emitter layer on which the etch stop mask is positioned, is formed of the high concentration emitter portion.
6. The manufacturing method of a selective emitter solar cell of claim 3 , wherein a position of the etch stop mask on the emitter layer is overlapped with a position to form the plurality of first electrodes.
7. The manufacturing method of a selective emitter solar cell of claim 6 , wherein a line width of the etch stop mask on the position to form the plurality of first electrodes equals a sum of the first line width of the first contact portion and the third line width of the first non-contact portion.
8. The manufacturing method of a selective emitter solar cell of claim 3 , wherein a position of the etch stop mask on the emitter layer is overlapped with a position to form the current collector.
9. The manufacturing method of a selective emitter solar cell of claim 8 , wherein a line width of the etch stop mask on the position to form the current collector equals a sum of the second line width of the second contact portion and the fourth line width of the second non-contact region.
10. The manufacturing method of a selective emitter solar cell of claim 1 , wherein the forming of the high concentration emitter portion includes:
forming the mask pattern on the emitter layer, the mask pattern having a hole pattern;
doping additionally an impurity of the second conductive type on the emitter layer through the hole pattern to form the high concentration emitter portion; and
removing the mask pattern.
11. The manufacturing method of a selective emitter solar cell of claim 1 , wherein the forming of the high concentration emitter portion is formed by the doping, and a doping depth of the high concentration emitter portion is more than a doping depth of the emitter layer.
12. The manufacturing method of a selective emitter solar cell of claim 1 , further comprising a hole pattern on the emitter layer, wherein a position of the hole pattern on the emitter layer is overlapped with a position to form the plurality of first electrodes.
13. The manufacturing method of a selective emitter solar cell of claim 12 , wherein a line width of the hole pattern on the position to form the plurality of first electrodes equals a sum of the first line width of the first contact portion and the third line width of the first non-contact portion.
14. The manufacturing method of a selective emitter solar cell of claim 1 , further comprising a hole pattern on the emitter layer, wherein a position of the hole pattern on the emitter layer is overlapped with a position to form the current collector.
15. The manufacturing method of a selective emitter solar cell of claim 14 , wherein a line width of the hole pattern on the position to form the current collector equals a sum of the second line width of the second contact portion and the fourth line width of the second non-contact portion.
16. The manufacturing method of a selective emitter solar cell of claim 1 , wherein the first non-contact portion has the same width on both sides of the first contact portion being in contact with the plurality of first electrodes.
17. The manufacturing method of selective emitter solar cell of claim 1 , wherein the first non-contact portion has a different width on both sides of the first contact portion being in contact with the plurality of first electrodes.
18. The manufacturing method of a selective emitter solar cell of claim 1 , wherein the first non-contact portion is formed only on one side of the first contact portion being in contact with the plurality of first electrodes.
19. The manufacturing method of a selective emitter solar cell of claim 1 , wherein the second non-contact portion has the same width on both sides of the second contact portion being in contact with the current collector.
20. The manufacturing method of a selective emitter solar cell of claim 1 , wherein the second non-contact portion has a different width on both sides of the second contact portion being in contact with the current collector.
21. The manufacturing method of a selective emitter solar cell of claim 1 , wherein the second non-contact portion is formed only on one side of the second contact portion being in contact with the current collector.
22. The manufacturing method of a selective emitter solar cell of claim 1 , wherein the third line width (W 3 ) of the first non-contact portion and the fourth line width (W 4 ) of the second non-contact portion are the same.