Black-coloured photovoltaic device

Patent metadata

Field	Value
Publication number	US-11966201-B2
Application number	US-202017432785-A
Country	US
Kind code	B2
Filing date	Feb 21, 2020
Priority date	Feb 21, 2019
Publication date	Apr 23, 2024
Grant date	Apr 23, 2024

Abstract

A photovoltaic device includes an electrically-conductive front contact layer; an electrically-conductive back contact layer, the back contact layer being intended to be situated further from a source of incident light than the front contact layer; and a semiconductor-based PIN junction having a substantially amorphous intrinsic silicon layer sandwiched between a P-type doped semiconductor layer and an N-type doped semiconductor layer. The layer of the PIN junction situated closest to the back contact layer is a silicon-germanium alloy layer including at least 2 mol % of germanium.

First claim

The invention claimed is:

1. A photovoltaic device comprising:
an electrically-conductive front contact layer;
an electrically-conductive back contact layer, said back contact layer being situated further from a source of incident light than said front contact layer; and
a semiconductor-based PIN junction comprising a substantially amorphous intrinsic silicon layer sandwiched between a P-type doped semiconductor layer and an N-type doped semiconductor layer,
wherein the layer of said PIN junction situated closest to said back contact layer is a silicon-germanium alloy layer comprising at least 2 mol % of germanium.

2. The photovoltaic device according to claim 1 , wherein said silicon-germanium layer comprises at least 10 mol % germanium.

3. The photovoltaic device according to claim 1 , further comprising an anti-reflective layer situated on a light-incident side of said front contact layer.

4. The photovoltaic device according to claim 3 , wherein said anti-reflective layer exhibits an index of refraction lower than an index of refraction of said front contact layer.

5. The photovoltaic device according to claim 1 , wherein a surface of the silicon-germanium alloy layer facing towards the front contact layer has an rms roughness of at least 10 nm.

6. The photovoltaic device according to claim 1 , further comprising a substantially-transparent substrate situated on a light-incident side of said front contact layer.

7. The photovoltaic device according to claim 6 , further comprising an anti-reflective coating disposed on a front side of said substantially-transparent substrate, said anti-reflective coating exhibiting an index of refraction lower than an index of refraction of said substrate.

8. The photovoltaic device according to claim 5 , wherein said front contact layer comprises at least one of zinc oxide and tin oxide.

9. The photovoltaic device according to claim 1 , further comprising a substrate arranged on a surface of said back contact layer facing away from a light-incident side of said back contact layer.

10. The photovoltaic device according to claim 9 , wherein said back contact layer comprises at least one of zinc oxide and tin oxide.

11. The photovoltaic device according to claim 1 , wherein the layers of the PIN junction other than that based on silicon-germanium alloy are based on amorphous silicon.

12. A timepiece comprising a photovoltaic device according to claim 1 .

13. The timepiece according to claim 12 , wherein said photovoltaic device forms at least part of a dial or a bezel comprised by said timepiece.

14. A method of manufacturing a photovoltaic device according to claim 1 wherein said silicon-germanium layer is deposited by plasma-assisted chemical vapour deposition under the following conditions for a reactor of 13.56 MHz plasma excitation frequency, 15 mm inter-electrode distance, and 45×55 cm electrode surface dimensions:
silane flow 30-50 sccm;
germane flow 6-10 sccm;
hydrogen flow 1200-1500 sccm;
phosphene flow 0.5-1.5 sccm, or diborane flow 0.5-1.5 sccm;
pressure 3.0-3.5 mbar; and
plasma power 100-150 W.

15. The photovoltaic device according to claim 1 , wherein said silicon-germanium alloy layer comprises 15% to 25% germanium.

16. The photovoltaic device according to claim 1 , wherein said silicon-germanium alloy layer comprises substantially 20% germanium.

Assignees

• Nivarox Far Sa

Inventors

• Bailat Julien
• Favre Elisa
• Schüttauf Jan-Willem

Classifications

• H10F71/1035

  having multiple Group IV elements, e.g. SiGe or SiC · CPC title

• H10F71/1215

  comprising at least two Group IV elements, e.g. SiGe · CPC title

• H10F77/1665

  including Group IV-IV materials, e.g. SiGe or SiC · CPC title

• H10F77/1648

  including microcrystalline Group IV-IV materials, e.g. microcrystalline SiGe · CPC title

• H10F77/244

  made of transparent conductive layers, e.g. transparent conductive oxide [TCO] layers · CPC title