Photoelectric conversion device fabrication method

• US 8,252,668 B2
• Filed: 08/18/2009
• Issued: 08/28/2012
• Est. Priority Date: 11/27/2008
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Yamaguchi, Kengo, Sakai, Satoshi, Takeuchi, Yoshiaki
• Primary Examiner(s): SARKAR, ASOK K
• Application Number:
  US13/003,936
• Publication Number:
  US 20110111551A1
• Time in Patent Office: 1,106 Days
• Field of Search: 136/249, 136/255, 136/258, 136/261, 257/E21.297, 257/E21.316, 438/96, 438/365, 438/482
• US Class Current: 438/485
• CPC Class Codes: H01L 31/046 PV modules composed of a plurality of thin film solar cells deposited on the same substrate
• CPC Class Codes: H01L 31/0463 characterised by special patterning methods to connect the PV cells in a module, e.g. laser cutting of the conductive or active layers
• CPC Class Codes: H01L 31/0745 comprising a AIVBIV heterojunction, e.g. Si/Ge, SiGe/Si or Si/SiC solar cells
• CPC Class Codes: H01L 31/077 the devices comprising monocrystalline or polycrystalline materials
• CPC Class Codes: H01L 31/1804 comprising only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 31/202 including only elements of Group IV of the Periodic Table
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y02E 10/548 Amorphous silicon PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

Provided is a photoelectric conversion device fabrication method that realizes both high productivity and high conversion efficiency by rapidly forming an n-layer having good coverage. The fabrication method for a photoelectric conversion device includes a step of forming a silicon photoelectric conversion layer on a substrate by a plasma CVD method. In the fabrication method for the photoelectric conversion device, the step of forming the photoelectric conversion layer includes a step of forming an i-layer formed of crystalline silicon and a step of forming, on the i-layer, an n-layer under a condition with a hydrogen dilution ratio of 0 to 10, inclusive.

Claims

1. A photoelectric conversion device fabrication method comprising forming a silicon photoelectric conversion layer on a substrate by using a plasma chemical vapor deposition (CVD) method, wherein

the forming the photoelectric conversion layer comprises:

forming an i-layer of crystalline silicon;

forming a first n-layer on the i-layer under a condition with a first hydrogen dilution ratio of 0 to 10, inclusive, and

forming a second n-layer on the first n-layer under a condition with a second hydrogen dilution ratio different from the first hydrogen dilution ratio.

2. A photoelectric conversion device fabrication method according to claim 1, wherein at least one of the first n-layer or the second n-layer is formed at a deposition rate of 0.2 nm/s or more.

3. A photoelectric conversion device fabrication method according to claim 2, wherein the first n-layer is formed of amorphous silicon.

4. A photoelectric conversion device fabrication method according to claim 2, wherein both the first and second n-layers are formed of amorphous silicon.

5. A photoelectric conversion device fabrication method according to claim 1, wherein the first n-layer is formed by using a material gas containing at least one element selected from the group consisting of carbon and nitrogen.

6. A photoelectric conversion device fabrication method according to claim 1, wherein

the first n-layer is formed by using a material gas containing hydrogen gas, silane (SiH₄) gas, and methane gas, and

a flow ratio of the methane gas to the SiH₄ gas is 0.2% to 1.2%, inclusive.

7. A photoelectric conversion device fabrication method according to claim 1, wherein the second hydrogen dilution ratio is higher than the first hydrogen dilution ratio.

8. A photoelectric conversion device fabrication method according to claim 1, wherein

the i-layer is formed mainly of microcrystalline silicon, and

the first and second n-layers are formed mainly of P-doped silicon.

9. A photoelectric conversion device fabrication method according to claim 1, further comprising forming a crystalline silicon p-layer on the substrate by using a plasma CVD method prior to forming the photoelectric conversion layer, wherein

the p-layer is formed mainly of B-doped microcrystalline silicon on the substrate,

the i-layer is formed mainly of microcrystalline silicon, and

the first and second n-layers are formed mainly of P-doped silicon.

10. A photoelectric conversion device fabrication method according to claim 1, wherein the first hydrogen dilution ratio of 0 to 10, inclusive, prevents a formation of crystalline silicon in the first n-layer.