Copper-based chalcogenide photovoltaic device and a method of forming the same

Patent metadata

Field	Value
Publication number	US-11322634-B2
Application number	US-201716311845-A
Country	US
Kind code	B2
Filing date	Jun 21, 2017
Priority date	Jun 21, 2016
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

A method for forming a photovoltaic device comprising the steps of: providing a first conductive material on a substrate; depositing a continuous layer of a dielectric material less than 10 nm thick on the first conductive material; annealing the first conductive material and the layer of dielectric material; forming a chalcogenide light-absorbing material on the layer of dielectric material; and depositing a second material on the light-absorbing material such that the second material is electrically coupled to the light-absorbing material; wherein the first conductive material and the dielectric material are selected such that, during the step of annealing, a portion of the first conductive material undergoes a chemical reaction to form: a layer of a metal chalcogenide material at the interface between first conductive material and the dielectric material; and a plurality of openings in the layer of dielectric material; the openings being such to allow electrical coupling between the light-absorbing material and the layer of a metal chalcogenide material. Additionally contemplated is a photovoltaic device formed by this method.

First claim

The invention claimed is:

1. A method for forming a photovoltaic device comprising the
steps of:
providing a first conductive material on a substrate;
depositing a layer of a dielectric material on the first conductive material, the layer of the dielectric material being continuous and being thinner than 10 nm;
depositing a plurality of precursor materials on the layer of the dielectric material;
annealing the first conductive material, the layer of the dielectric material and the plurality of precursor materials in a chalcogen atmosphere to form a chalcogenide light-absorbing material on the layer of the dielectric material; and
depositing a second material on the light-absorbing material such that the second material is electrically coupled to the light-absorbing material;
wherein during the step of annealing:
the plurality of precursors react to form the chalcogenide light-absorbing material; and

wherein the first conductive material and the dielectric material are selected such that, during the step of annealing, a portion of the first conductive material undergoes a chemical reaction to form:
a layer of a metal chalcogenide material at the interface between first conductive material and the dielectric material; and
a plurality of openings in the layer of the dielectric material; the openings being such to allow electrical coupling between the light-absorbing material and the layer of the metal chalcogenide material; and

wherein the portion of the first conductive material that undergoes the chemical reaction during the annealing expands in volume and applies a tensile stress to a lattice structure of the layer of the dielectric material so that the lattice structure is altered to form a self-organized nano-pattern of openings in the layer of the dielectric material.

2. The method of claim 1 wherein the step of depositing the layer of the dielectric material on the first conductive material is performed in a manner such that, before the annealing step is performed, the plurality of precursor materials and the first conductive material are electrically insulated.

3. The method of claim 1 wherein the step of depositing the layer of the dielectric material on the first conductive material is performed in a manner such that formation of voids in the region between the light-absorbing layer and the first conductive material is reduced.

4. The method of claim 1 wherein the layer of the metal chalcogenide material is such to allow electrical conduction from the first conductive material to the light-absorbing material during operation of the photovoltaic device.

5. The method of claim 1 , wherein during the step of annealing, sulphur or selenium diffuses through the layer of the dielectric material to react with molybdenum of the first conductive material to form molybdenum sulphide or molybdenum selenide.

6. The method of claim 5 wherein a portion of the sulphur or selenium diffusing through the layer of the dielectric material originates from the chalcogenide light-absorbing material.

7. The method of claim 1 , wherein the layer of the metal chalcogenide material has a thickness comprised between 20 nm and 150 nm.

8. The method of claim 1 , wherein the openings in the layer of the dielectric material have a diameter comprised between 50 nm and 250 nm.

9. The method of claim 1 , wherein a surface density of the openings in the layer of the dielectric material is comprised between 6×10 8 openings/cm 2 and 10×10 10 openings/cm 2 .

10. A method for forming a photovoltaic device comprising the steps of:
providing a first conductive material on a substrate;
depositing a layer of a dielectric material on the first conductive material, the layer of the dielectric material being continuous and being thinner than 10 nm;
annealing the first conductive material and the layer of the dielectric material;
depositing a plurality of precursor materials on the layer of the dielectric material;
annealing the first conductive material, the layer of the dielectric material and the plurality of precursor materials in a chalcogen atmosphere to form a chalcogenide light-absorbing material on the layer of the dielectric material; and
depositing a second material on the light-absorbing material such that the second material is electrically coupled to the light-absorbing material;
wherein the first conductive material and the dielectric material are selected such that, during the step of annealing the first conductive material and the layer of the dielectric material, a portion of the first conductive material undergoes a chemical reaction to form:
a layer of a metal chalcogenide material at the interface between first conductive material and the dielectric material; and
a plurality of openings in the layer of the dielectric material; the openings being such to allow electrical coupling between the light-absorbing material and the layer of the metal chalcogenide material.

11. The method of claim 10 , wherein the step of depositing the layer of the dielectric material on the first conductive material is performed in a manner such that formation of voids in the region between the light-absorbing layer and the first conductive material is reduced.

12. The method of claim 10 , wherein, during the step of annealing the first conductive material and the layer of the dielectric material, the portion of the first conductive material that undergoes a chemical reaction expands in volume and applies a tensile stress to the lattice structure of the layer of the dielectric material so that the structure is altered and a self-organised nano-pattern of openings is formed in the layer of the dielectric material.

13. The method of claim 10 , wherein the layer of the metal chalcogenide material is such to allow electrical conduction from the first conductive material to the light-absorbing material during operation of the photovoltaic device.

14. The method of claim 10 , wherein during the step of annealing the first conductive material and the layer of the dielectric material, sulphur or selenium diffuses through the layer of the dielectric material to react with molybdenum of the first conductive material to form molybdenum sulphide or molybdenum selenide.

Assignees

• Newsouth Innovations Pty Ltd

Inventors

• Hao Xiaojing
• Liu Fangyang
• Huang Jialiang
• Yan Chang
• Sun Kaiwen
• Green Martin Andrew

Classifications

• H10P14/3436

  being chalcogenide semiconductor materials not being oxides, e.g. ternary compounds · CPC title

• H10P14/3248

  consisting of two layers · CPC title

• H10P14/3238

  being insulating materials · CPC title

• H10P14/3241

  being conductive materials · CPC title

• H10P14/2922

  being non-crystalline insulating materials, e.g. glass or polymers · CPC title