Kesterite material of CZTS, CZTSe or CZTSSe type

Patent metadata

Field	Value
Publication number	US-11087976-B2
Application number	US-201716324114-A
Country	US
Kind code	B2
Filing date	Sep 1, 2017
Priority date	Oct 7, 2016
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

A method of producing a kesterite material of CZTS, CZTSe or CZTSSe type, including the steps of: a) preparing an acidic solution by dissolving copper and zinc salts in water in desired molar ratio, b) preparing a basic solution by dissolving an alkali metal stannate together with an alkali metal carbonate or an alkali metal hydrogen carbonate or an alkali metal hydroxide or a combination thereof, and optionally with an alkali metal selenate or an alkali metal selenite or a mixture thereof, c) carrying out a precipitation reaction by mixing the acidic and the basic solution, d) drying the precipitate thereby providing a precursor for the kesterite material, and e) sulfurizing the precursor of step d to provide the kesterite material. Also, a precursor for a kesterite material of CZTS, CZTSe or CZTSSe type.

First claim

The invention claimed is:

1. A method of producing a kesterite material of CZTS, CZTSe or CZTSSe type, comprising the steps of:
a) preparing an acidic solution and dissolving copper salt and zinc salt in water in desired molar ratio,
b) preparing a basic solution by dissolving an alkali metal stannate together with an alkali metal carbonate or an alkali metal hydrogen carbonate or an alkali metal hydroxide or a combination thereof, and optionally with an alkali metal selenate or an alkali metal selenite or a mixture thereof,
c) carrying out a precipitation reaction by mixing said acidic and said basic solution, thereby obtaining a precipitate,
d) washing and heat treating said precipitate thereby providing a precursor for the kesterite material, and
e) sulfurizing the precursor of step d to provide the kesterite material.

2. The method according to claim 1 , wherein the salts used for the acidic solution are nitrates, halides, sulfates, carboxylates or combinations thereof.

3. The method according to claim 1 , wherein the copper salt is copper (II) nitrate and the zinc salt is zinc (II) nitrate.

4. The method according to claim 1 , wherein said acidic solution further comprises nitric acid.

5. The method according to claim 1 , wherein said alkali metal stannate comprises Na 2 SnO 3 and/or K 2 SnO 3 in hydrated or anhydrous form.

6. The method according to claim 1 , wherein said basic solution further comprises selenium in the form of an alkali metal selenate and/or an alkali metal selenite.

7. The method according to claim 1 , wherein the step of sulfurizing comprises subjecting the precursor to a sulfur comprising gas at a temperature above room temperature.

8. The method according to claim 7 , wherein said sulfur comprising gas is one or more of the following: H 2 S, elemental sulfur in gaseous state (S 2 -S 8 ), COS, CS 2 , organic sulfur compounds.

9. The method according to claim 8 , wherein said organic sulfur compounds are CH 3 SH and/or CH 3 SSCH 3 .

10. The method according to claim 1 , wherein said sulfur comprising gas further comprises selenium.

11. The method according to claim 1 , further comprising the following steps between steps d) and e):
grinding the precursor for the kesterite material obtained by step d),
dispersing said grinded precursor in a liquid, thereby obtaining a slurry,
depositing a thin layer of the slurry onto a substrate, and
optionally, drying said thin layer.

12. The method according to claim 11 , wherein the step of dispersing said grinded precursor in a liquid comprises wetting and dispersing said grinded precursor in a liquid using polymeric wetting and/or dispersion agents.

13. The method according to claim 1 , further comprising the following steps subsequent to step e):
grinding said kesterite material,
dispersing said grinded kesterite material in a liquid, thereby obtaining a slurry,
depositing a thin layer of the slurry onto a substrate,
optionally, drying said thin layer, and
optionally, heat treating such thin layer.

14. The method according to claim 13 , wherein the step of dispersing said grinded kesterite material in a liquid comprises wetting and dispersing said grinded kesterite material in a liquid using polymeric wetting and/or dispersion agents.

15. A precursor material for a kesterite material of CZTS, CZTSe or CZTSSe type, where said precursor material is obtained by a process comprising the steps of:
a) preparing an acidic solution and dissolving copper salt and zinc salt in water in a desired molar ratio,
b) preparing a basic solution by dissolving an alkali metal stannate together with an alkali metal carbonate or an alkali metal hydrogen carbonate or an alkali metal hydroxide or a combination thereof,
c) carrying out a precipitation reaction by mixing the acidic and the basic solutions, thereby obtaining a precipitate, and
d) washing and heat treating the precipitate thereby providing a precursor for the kesterite material.

Assignees

• Haldor Topsoe As

Inventors

• Schjødt Niels Christian
• Dahl Søren
• Nerlov Jesper

Classifications

• H10P14/3412 Primary

  including tin · CPC title

• H10F77/128

  comprising only Group I-II-IV-VI kesterite materials, e.g. Cu2ZnSnSe4 or Cu2ZnSnS4 · CPC title

• C01G19/006 Primary

  Compounds containing tin, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C01B19/002

  Compounds containing, besides selenium or tellurium, more than one other element, with -O- and -OH not being considered as anions · CPC title

• C01P2002/77

  by unit-cell parameters, atom positions or structure diagrams · CPC title