EP0093514A1
Expired / Lapsed
EP
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Amorphous silicon solar cell incorporating an insulating layer to suppress back diffusion of holes into an N-type region and method of fabrication thereof
Assignee: Chevron USA Inc
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Filing: 1983-04-07
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Granted: —
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Expires: 2003-04-07
Abstract
Abstract In an hydrogenated amorphous silicon solar cell which includes a body of hydrogenated amorphous silicon having layers of differing conductivity (14,16 and 20) with an interface between a photoactive intrinsic hydrogenated amorphous silicon layer (16) and an incident N-type layer (20) of hydrogenated amorphous silicon, the back diffusion of holes into the N-type layer is reduced by positioning between the photoactive layer (16) and the N-type layer (20) a thin layer (18) of insulator material, such as Si 3 N 4 or Si0 2 . The solar cell is advantageously fabricated in a glow discharge apparatus.
Inventors
- 👤 Arun Madan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 23:08
CPC Classifications
H; H10; H10F; H10F10/00; H10F10/10; H10F10/17; H10F10/172; H10F71/00; H10F71/10; H10F71/103; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/548; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
90 words
An hydrogenated amorphous silicon solar cell which comprises a body of hydrogenated amorphous silicon having layers of differing conductivity including an incident N-type or N +- type layer of hydrogenated amorphous silicon and a photoactive intrinsic hydrogenated amorphous silicon layer, characterized in that the body of hydrogenated amorphous silicon incorporates an insulating layer between said incident N-type or N+ -type layer and said photoactive intrinsic silicon layer, said insulating layer having a thickness such as to reflect holes back into the photoactive intrinsic layer whilst permitting electrons to pass therethrough.
Claim 2
Dependent Claim
90 words
An hydrogenated amorphous silicon solar cell which comprises a body of hydrogenated amorphous silicon having layers of differing conductivity including an incident N-type or N +- type layer of hydrogenated amorphous silicon and a photoactive intrinsic hydrogenated amorphous silicon layer, characterized in that the body of hydrogenated amorphous silicon incorporates an insulating layer between said incident N-type or N+ -type layer and said photoactive intrinsic silicon layer, said insulating layer having a thickness such as to reflect holes back into the photoactive intrinsic layer whilst permitting electrons to pass therethrough.
Claim 3
Dependent Claim
19 words
A solar cell as claimed in Claim 1, wherein the insulating layer is from 1 to 5 nanometers thick.
Claim 4
Dependent Claim
42 words
A solar cell as claimed in Claim 1 or 2, wherein the insulating layer is formed from an insulator material selected from Si 3 N 4 , Si0 2 , BN, T a 2 0 5 and Nb 2 0 5 .
Claim 5
Dependent Claim
18 words
A solar cell as claimed in Claim 3, wherein the insulator material is Si 3 N 4 .
Claim 6
Dependent Claim
16 words
A solar cell as claimed in Claim 3, wherein the insulator material is SiO 2 .
Claim 7
Dependent Claim
26 words
A solar cell as claimed in any preceding claim, wherein the cell has the layered structure of N-type amorphous silicon/insulator material/photoactive intrinsic amorphous silicon/P-type amorphous silicon.
Claim 8
Dependent Claim
47 words
A solar cell as claimed in Claim 6, wherein the P-type amorphous silicon layer is from 20 to 50 nanometers in thickness, the photoactive intrinsic silicon layer is from 400 to 1,000 nanometers in thickness, and the N-type layer is from 10 to 40 nanometers in thickness.
Claim 9
Dependent Claim
28 words
A solar cell as claimed in Claim 6 or 7, wherein a plurality of the solar cells are stacked, with the cells being separated by a tunnel junction.
Claim 10
Independent Claim
91 words
A method of inhibiting the transfer of holes from a layer of photoactive intrinsic hydrogenated amorphous silicon to an incident N-type layer of hydrogenated amorphous silicon in interfacial contact therewith, which comprises: fabricating an insulating layer between said N-type layer of hydrogenated amorphous silicon and the photoactive intrinsic hydrogenated amorphous silicon layer, said insulating layer having an electron affinity which is substantially the same as that of the amorphous silicon and a thickness which maximizes the quantum efficiency of the amorphous silicon at the blue end of the AM1 excitation spectrum.
Claim 11
Independent Claim
91 words
A method of inhibiting the transfer of holes from a layer of photoactive intrinsic hydrogenated amorphous silicon to an incident N-type layer of hydrogenated amorphous silicon in interfacial contact therewith, which comprises: fabricating an insulating layer between said N-type layer of hydrogenated amorphous silicon and the photoactive intrinsic hydrogenated amorphous silicon layer, said insulating layer having an electron affinity which is substantially the same as that of the amorphous silicon and a thickness which maximizes the quantum efficiency of the amorphous silicon at the blue end of the AM1 excitation spectrum.
Claim 12
Dependent Claim
18 words
A method according to Claim 9, wherein the insulating layer is from 1 to 5 nanometers in thickness.
Claim 13
Dependent Claim
35 words
A method according to Claim 9 or 10, wherein the insulating layer is formed from an insulator material selected from Si3N4, Si0 2 , BN, Ta 2 0 5 and Nb 2 O 5 .
Claim 14
Dependent Claim
40 words
A method according to Claim 11, wherein the insulator material is Si 3 N 4 which is fabricated by a glow discharge in an atmosphere comprising 70% SiH 4 and 30% NH 3 with a substrate temperature of about 280°C.
Claim 15
Dependent Claim
37 words
A method according to Claim 11, wherein the insulator material is Si0 2 which is fabricated by a glow discharge in a 50/50 mixture SiH 4 and N 2 0 with a substrate temperature of about 280°C.
References Cited (Backward Citations)
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