METHOD OF MANUFACTURING AN AMORPHOUS/CRYSTALLINE SILICON HETEROJUNCTION SOLAR CELL

• US 20090293948A1
• Filed: 05/28/2008
• Published: 12/03/2009
• Est. Priority Date: 05/28/2008
• Status: Abandoned Application

• Current Assignee: Stichting Energieonderzoek Centrum Nederland
• Original Assignee: Stichting Energieonderzoek Centrum Nederland
• Inventors: Salza, E., Caputo, D., Nascetti, A., Geerlings, Lambert Johan, Tucci, Mario, Serenelli, L., Ratte, M., De Iuliis, Simona
• Application Number:
  US12/128,109
• Publication Number:
  US 20090293948A1
• Time in Patent Office: Days
• US Class Current: 136/256
• CPC Class Codes: H01L 21/32055 Deposition of semiconductive layers, e.g. poly - or amorphous silicon layers
• CPC Class Codes: H01L 21/32137 of silicon-containing layers
• CPC Class Codes: H01L 31/02168 the coatings being antireflective or having enhancing optical properties for the solar cells
• CPC Class Codes: H01L 31/022441 Electrode arrangements specially adapted for back-contact solar cells
• CPC Class Codes: H01L 31/0747 comprising a heterojunction of crystalline and amorphous materials, e.g. heterojunction with intrinsic thin layer
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02E 10/548 Amorphous silicon PV cells

Abstract

A method for manufacturing a solar cell includes

• • providing a first conductivity type doped crystalline silicon wafer,
  • depositing on one side a first intrinsic a-Si:H buffer layer, followed by a second conductivity type doped a-Si:H layer,
  • turning over the wafer and depositing on the opposite side a surface passivating anti-reflection coating,
  • applying a first mask having a grid opening on the second conductivity type doped a-Si:H covered surface of the wafer,
  • dry etching to remove the second conductivity type doped a-Si:H layer not covered by the first mask,
  • while maintaining the first mask in position:
    • depositing a second intrinsic buffer layer of a-Si:H,
    • depositing a first conductivity type doped a-Si:H layer.

Claims

1. Method for manufacturing a solar cell, comprising

providing a first conductivity type doped crystalline silicon safer

depositing on one side a first intrinsic a-Si:

H buffer layer, followed by an second conductivity type doped a-Si;

H layer,

turning over the wafer and depositing on the opposite side a surface passivating anti-reflection coasting,

applying a first mask having a grid opening on the second conductivity type doped a-Si;

H covered surface of the wafer,

dry etching to remove the second conductivity type doped a-Si;

H layer not covered by the first mask,

while maintaining the first mask in position;

depositing a second intrinsic buffer layer of a-Si;

H,

depositing a first conductivity type doped a-Si;

H layer.

2. Method for manufacturing a solar cell according to claim 1, comprising:

depositing a first contact material layer on the first conductivity type doped a-Si;

H layer, while maintaining the first mask in position.

3. Method for manufacturing a solar cell according to claim 1, comprising:

applying a second mask and depositing through the second mask a second contact material layer on the second conductivity type doped a-Si;

H layer

4. Method for manufacturing a solar cell according to claim 1, wherein the first mask has a comb shaped grid opening.

5. Method for manufacturing a solar cell according to claim 3, wherein applying the second mask is performed by rotating the first mask over 180 degrees on the wafer.

6. Method for manufacturing a solar cell according to claim 1, wherein the first conductivity type is p-type and the second conductivity type is n-type.

7. Method for manufacturing a solar cell according to claim 1, wherein the first conductivity type is n-type and the second conductivity type is p-type.

8. Method for manufacturing a solar cell according to claim 2, wherein the first contact material layer on the first conductivity type doped a-Si:

H layer is Al.

9. Method for manufacturing a solar cell according to claim 3, wherein the second contact material/layer on the second conductivity type doped a-Si:

H layer is Ag.

10. Method for manufacturing a solar cell according to claim 3, further comprising depositing a first contact material layer on the first conductivity type doped a-Si:

H layer, while maintaining the first mask in wherein the first contact material/layer on the first conductivity type doped a-Si;

H layer and the second contact material/layer on the second conductivity type doped a-Si;

H layer are comb shaped.

11. Method for manufacturing a solar cell according to claim 3, further comprising depositing a first contact material layer on the first conductivity type doped a-Si:

H layer, while maintaining the first mask in position, and wherein the first contact material layer on the first conductivity type doped a-Si;

H layer and the second contact material/layer on the second conductivity type doped a-Si;

H layer are interdigitated.

12. Method for manufacturing a solar cell according to claim 1, wherein the surface passivating anti-reflection coating is an a-Si:

H/SiNx double layer.

13. Method for manufacturing a solar cell according to claim 1, wherein the one side of the crystalline silicon wafer is a polished side of the wafer.

14. Method for manufacturing a solar cell according to claim 1, wherein the distance between adjacent fingers of the interdigitated combs is dimensioned supposed to the diffusion length of minority photo generated carriers.

15. Method for manufacturing a solar cell according to claim 14, wherein the diffusion length is in the order of 400 μ

m.

16. Method for manufacturing a solar cell according to claim 1, wherein processing is performed at temperature below 300°

C.

17. Solar cell comprising an emitter and a back surface field as rear-junctions with back side contacting, and a grid-less front surface passivated by a surface passivating anti-reflection coating;

the emitter and the back surface field both formed by a a-Si;

H/c-Si heterostructures, the back side contacting of the emitter being interdigitated with the backside contacting of the back surface field, wherein the solar cell comprises;

a first conductivity type doped crystalline silicon wafer;

on the one side an intrinsic a-Si;

H buffer layer, followed by an second conductivity type doped a-Si;

H layer;

the solar cell on the second conductivity type doped a-Si;

H covered surface of the wafer comprising a grid opening to the intrinsic a-Si;

H buffer layer or to the c-Si substrate,

in which opening a stack is located of an Intrinsic buffer layer of a-Si;

H and a first conductivity type doped a-Si;

H layer.

18. Solar Cell according to claim 17, wherein a contact of a first contact material is located on the first conductivity type doped a-Si:

H layer of the stack.

19. Solar cell according to claim 17, wherein a contact of a second contact material is located on the second conductivity type doped a-Si:

H layer.

20. Solar cell according to claim 17, wherein the surface passivating anti-reflection coating on the side opposite the one side comprises an a-Si:

H/SiNx double layer.