Method for fabricating back-contact type solar cell

1. A method for fabricating a back-contact type solar cell, the method consisting essentially of following steps:

(a) providing a semiconductor substrate;

(b) roughening a light-receiving surface of the semiconductor substrate;

(c) forming a plurality of phosphorus-containing pastes on a back surface of the semiconductor substrate;

(d) performing a phosphorus diffusion process on the semiconductor substrate, wherein the phosphorus-containing pastes enter the semiconductor substrate to form a plurality of n-type heavily doped zones in the a back surface of the semiconductor substrate, and the phosphorus of the phosphorus diffusion process are diffused into the light-receiving surface of the semiconductor substrate to form a front surface field layer in the light receiving surface of the semiconductor substrate and to form a n-type lightly doped layer in the back surface and a plurality of side surfaces of the semiconductor substrate;

(e) removing the n-type lightly doped layer;

(f) forming a front anti-reflection layer on the front surface field layer, and a back anti-reflection layer on the back surface;

(g) printing a plurality of lead-containing silver pastes on the back anti-reflection layer, wherein the lead-containing silver pastes are disposed corresponding to the n-type heavily doped zones, respectively;

(h) printing a plurality of lead-containing aluminum pastes on the back anti-reflection layer, wherein the lead-containing aluminum pastes are disposed corresponding to a plurality of p-typed contacting regions of the back-contact type solar cell; and

(i) sintering the lead-containing silver pastes and the lead-containing aluminum pastes for forming a plurality of electrodes.

2. The method for fabricating a back-contact type solar cell of claim 1 , wherein the step (b) comprises performing a wet etching process on the semiconductor substrate.

3. The method for fabricating a back-contact type solar cell of claim 1 , wherein the step (e) comprises soaking the semiconductor substrate in a hydrogen fluoride solution to remove a phosphosilicate glass on the semiconductor substrate.

4. The method for fabricating a back-contact type solar cell of claim 1 , wherein the front anti-reflection layer and the back anti-reflection layer in the step (f) are dielectric layers.

5. The method for fabricating a back-contact type solar cell of claim 1 , wherein the step (g) comprises curing the lead-containing silver pastes.

6. The method for fabricating a back-contact type solar cell of claim 1 , wherein the step (h) comprises curing the lead-containing aluminum pastes.

7. The method for fabricating a back-contact type solar cell of claim 1 , wherein the step (i) comprises:

making the lead-containing silver pastes pass through the back anti-reflection layer, and contact the n-type heavily doped zones.

8. The method for fabricating a back-contact type solar cell of claim 1 , wherein the step (i) comprises:

making the lead-containing aluminum pastes pass through the back anti-reflection layer, and the aluminum of the lead-containing aluminum pastes enters the semiconductor substrate to forms a plurality of p-type heavily doped zones, and the lead-containing aluminum pastes connect to the p-type heavily doped zones, respectively, wherein the n-type heavily doped zones are spaced from the p-type heavily doped zones, and the n-type heavily doped zones and the p-type heavily doped zones are alternately arranged.

9. A method for fabricating a back-contact type solar cell, the method consisting essentially of following steps:

(a) providing a semiconductor substrate;

(b) roughening a light receiving surface of the semiconductor substrate;

(c) performing a phosphorus diffusion process on the semiconductor substrate, wherein the phosphorus of the phosphorus diffusion process are diffused into the semiconductor substrate to form a front surface field layer in the light receiving surface of the semiconductor substrate and a n-type doped layer in the back surface and a plurality of side surfaces of the semiconductor substrate;

(d) removing the n-type doped layer;

(e) forming a plurality of n-type doped zones in a back surface of the semiconductor substrate;

(f) forming a plurality of p-type doped zones in the back surface of the semiconductor substrate, wherein the n-type doped zones are spaced from the p-type doped zones;

(g) forming a front anti-reflection layer on the front surface field layer, and a back anti-reflection layer on the back surface;

(h) printing a plurality of conductive pastes on the back anti-reflection layer, wherein the conductive pastes are disposed corresponding to the n-type doped zones and the p-type doped zones, respectively; and

(i) sintering the conductive pastes for forming a plurality of electrodes.

10. The method for fabricating a back-contact type solar cell of claim 9 , wherein the step (b) comprises performing a wet etching process on the semiconductor substrate.

11. The method for fabricating a back-contact type solar cell of claim 9 , wherein the step (d) comprises soaking the semiconductor substrate in a hydrogen fluoride solution to remove a phosphosilicate glass on the semiconductor substrate.

12. The method for fabricating a back-contact type solar cell of claim 9 , wherein the step (e) is performed through ion implantation.

13. The method for fabricating a back-contact type solar cell of claim 9 , wherein the step (f) is performed through ion implantation.

14. The method for fabricating a back-contact type solar cell of claim 9 , wherein the front anti-reflection layer and the back anti-reflection layer in the step (g) are dielectric layers.

15. The method for fabricating a back-contact type solar cell of claim 9 , wherein the step (i) comprises:

making the conductive pastes pass through the back anti-reflection layer, and contact the n-type doped zones and the p-type doped zones respectively.

16. A method for fabricating a back-contact type solar cell, the method consisting essentially of following steps:

(a) providing a semiconductor substrate;

(b) roughening a light receiving surface of the semiconductor substrate;

(c) forming a mask layer on the light receiving surface;

(d) performing a boron ions diffusion process on the semiconductor substrate to form a p-type doped layer in the back surface and a plurality of side surfaces of the semiconductor substrate;

(e) removing the mask layer;

(f) patterning the p-type doped layer to form a plurality of grooves and a plurality of p-type doped zones in the back surface, wherein the grooves and the p-type doped zones are alternately arranged;

(g) forming a front surface field layer on the light receiving surface, and a plurality of n-type doped zones in the grooves, wherein the n-type doped zones are spaced from the p-type doped zones;

(h) forming a front anti-reflection layer on the front surface field layer, and a back anti-reflection layer on the back surface;

(i) printing a plurality of conductive pastes on the back anti-reflection layer, wherein the conductive pastes are disposed corresponding to the n-type doped zones and the p-type doped zones, respectively; and

(j) sintering the conductive pastes for forming a plurality of electrodes.

17. The method for fabricating a back-contact type solar cell of claim 16 , wherein the step (b) comprises performing a wet etching process on the semiconductor substrate.

18. The method for fabricating a back-contact type solar cell of claim 16 , wherein the mask layer in the step (c) comprises a material of silicon nitrides.

19. The method for fabricating a back-contact type solar cell of claim 16 , wherein the step (e) comprises soaking the semiconductor substrate in a hydrogen fluoride solution to remove the mask layer.

20. The method for fabricating a back-contact type solar cell of claim 16 , wherein the step (f) comprises:

partially disposing a protective layer on the p-type doped layer and exposing a plurality of predetermined regions of the grooves; and

etching the p-type doped layer and the semiconductor substrate.

21. The method for fabricating a back-contact type solar cell of claim 16 , wherein the step (g) is performed through ion implantation or a diffusion process.

22. The method for fabricating a back-contact type solar cell of claim 16 , wherein the front anti-reflection layer and the back anti-reflection layer in the step (h) are dielectric layers.

23. The method for fabricating a back-contact type solar cell of claim 16 , wherein the step (j) comprises:

making the conductive pastes pass through the back anti-reflection layer, and contact the n-type doped zones and the p-type doped zones, respectively.

24. A method for fabricating a back-contact type solar cell, the method consisting essentially of following steps:

(a) providing a semiconductor substrate;

(b) roughening a light receiving surface of the semiconductor substrate;

(c) forming a front surface field layer in the light-receiving surface;

(d) forming a plurality of n-type doped zones in the back surface of the semiconductor substrate;

(e) forming a mask layer on the front surface field layer and covering the n-type doped zones;

(f) performing a boron ion doping process on the semiconductor substrate to form a plurality of p-type doped zones in the semiconductor substrate where the mask layer uncovers;

(g) annealing the semiconductor substrate;

(h) removing the mask layer;

(i) forming a front anti-reflection layer on the front surface field layer, and a back anti-reflection layer on the back surface;

(j) printing a plurality of conductive pastes on the back anti-reflection layer, wherein the conductive pastes are disposed corresponding to the n-type doped zones and the p-type doped zones, respectively;

(k) sintering the conductive pastes for forming a plurality of electrodes; and

(l) forming a plurality of grooves on the back surface for isolating the n-type doped zones from the p-type doped zones.

25. The method for fabricating a back-contact type solar cell of claim 24 , wherein the step (b) comprises performing a wet etching process on the semiconductor substrate.

26. The method for fabricating a back-contact type solar cell of claim 24 , wherein the step (c) is performed through ion implantation or a diffusion process.

27. The method for fabricating a back-contact type solar cell of claim 24 , wherein the step (d) is performed through ion implantation or a diffusion process.

28. The method for fabricating a back-contact type solar cell of claim 24 , wherein the mask layer in the step (e) comprises a material of silicon nitrides.

29. The method for fabricating a back-contact type solar cell of claim 24 , wherein the step (h) comprises soaking the semiconductor substrate in a hydrogen fluoride solution.

30. The method for fabricating a back-contact type solar cell of claim 24 , wherein the front anti-reflection layer and the back anti-reflection layer in the step (i) are dielectric layers.

31. The method for fabricating a back-contact type solar cell of claim 24 , wherein the step (k) comprises:

making the conductive pastes pass through the back anti-reflection layer, and contact the n-type doped zones and the p-type doped zones respectively.

32. The method for fabricating a back-contact type solar cell of claim 24 , wherein the grooves in the step (l) are formed by laser cutting the semiconductor substrate.