Atomic layer epitaxy of hematite on indium tin oxide for application in solar energy conversion

Patent metadata

Field	Value
Publication number	US-9388499-B2
Application number	US-201414288998-A
Country	US
Kind code	B2
Filing date	May 28, 2014
Priority date	May 28, 2014
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

A method to provide an article of manufacture of iron oxide on indium tin oxide for solar energy conversion. An atomic layer epitaxy method is used to deposit an uncommon bixbytite-phase iron (III) oxide (β-Fe 2 O 3 ) which is deposited at low temperatures to provide 99% phase pure β-Fe 2 O 3 thin films on indium tin oxide. Subsequent annealing produces pure α-Fe 2 O 3 with well-defined epitaxy via a topotactic transition. These highly crystalline films in the ultra thin film limit enable high efficiency photoelectrochemical chemical water splitting.

First claim

What is claimed is:

1. A method of manufacturing a thin film article of manufacture for performing photochemical water oxidation, comprising the steps of,
providing a substrate;
epitaxially depositing an indium oxide layer on the substrate; and
epitaxially depositing a β-Fe 2 O 3 layer on the indium oxide.

2. The method as defined in claim 1 wherein the substrate comprises a cleaned yttria stabilized zirconia.

3. The method as defined in claim 2 wherein the step of epitaxially depositing the indium oxide comprises forming an indium tin oxide (ITO) layer epitaxially on the substrate.

4. The method as defined in claim 1 wherein the deposition steps are performed by at least one of atomic layer deposition (ALD) and sputtering.

5. The method as defined in claim 4 wherein the ALD method is performed at a chamber temperature of about 200-250° C.

6. The method as defined in claim 1 wherein the epitaxially deposited β-Fe 2 O 3 layer was deposited using Fe(Cp) 2 and O 3 .

7. The method as defined in claim 1 wherein the epitaxially deposited β-Fe 2 O 3 comprises about 99% by volume of the epitaxially deposited β-Fe 2 O 3 layer.

8. The method as defined in claim 3 wherein the epitaxially deposited ITO layer is selected from the group of low index layers of (100), (110) and (111).

9. The method as defined in claim 2 wherein the yttria stabilized zirconia comprises surface planar layers selected from the group of (001), (011) and (111).

10. The method as defined in claim 1 further including a step of annealing the thin film article, thereby topotactially transforming the epitaxially deposited β-Fe 2 O 3 layer to an α-Fe 2 O 3 (hematite) layer.

11. The method of claim 1 , wherein the epitaxially deposited β-Fe 2 O 3 layer is about 5 nm thick has a thickness of about 5 nm.

12. The method of claim 11 , wherein the epitaxially deposited indium oxide layer has a thickness of less than about 20 nm.

Assignees

• Uchicago Argonne Llc

Inventors

• Martinson Alex B
• Riha Shannon
• Guo Peijun
• Emery Jonathan D

Classifications

• C30B25/183

  being provided with a buffer layer, e.g. a lattice matching layer · CPC title

• C30B29/16

  Oxides · CPC title

• C30B25/10

  Heating of the reaction chamber or the substrate · CPC title

• H01G9/2027

  comprising an oxide semiconductor electrode · CPC title

• C23C16/45525

  Atomic layer deposition [ALD] · CPC title