NO GRAIN BOUNDARY CRYSTAL Cu2S THIN FILMS FOR SOLAR ENERGY CONVERSION

Patent metadata

Field	Value
Publication number	US-2018204972-A1
Application number	US-201815862561-A
Country	US
Kind code	A1
Filing date	Jan 4, 2018
Priority date	Jan 18, 2017
Publication date	Jul 19, 2018
Grant date	—

Abstract

The present invention comprises thin film Cu 2 S with ultra-large grains or in the best case no grain boundaries (a single crystal thin film). Based on our recent successes in atomic layer epitaxy of other materials we sought and found a suitable substrate (namely GaAs) that induces what appear to be Cu 2 S single crystal thin films.

First claim

What is claimed is:

1 . An article of manufacture comprising:
a substrate having a a thin film of Cu 2 S deposited on the substrate; wherein the Cu 2 S thin film has no effective grain boundaries.

2 . The article of manufacture of claim 1 , wherein the substrate presents a hexagonal lattice with constant between 3.6 and 4.4 Angstroms.

3 . The article of manufacture of claim 1 , wherein the article of manufacture has a photovoltaic efficiency of greater than 10%.

4 . The article of manufacture of claim 1 , wherein the thin film is deposited on a <111> surface of the substrate.

5 . The article of manufacture of claim 1 , wherein the substrate is GaA.

6 . The article of manufacture of claim 1 , wherein the thin film is a single crystal.

7 . The article of manufacture of claim 1 , further comprising an intervening layer between the substrate and the thin film.

8 . The article of manufacture of claim 1 , wherein the substrate and the thin film have a lattice mismatch of less than 10%.

9 . A method of manufacture comprising:
providing a substrate; epitaxially depositing a thin film of Cu 2 S; wherein the substrate and the thin film are latticed matched to within 10%.

10 . The method of manufacture of claim 9 , wherein the substrate is GaA.

11 . The method of manufacture of claim 9 , wherein the epitaxial ALD is at below below 225° C.

12 . The method of manufacture of claim 9 , wherein the epitaxial ALD is at below below 200° C.

13 . The method of manufacture of claim 9 , wherein the thin film has a thickness of between 0.1 and 5000 nm.

14 . The method of manufacture of claim 9 , further comprising, prior to epitaxially depositing the thin film, depositing an intervening layer on the substrate, wherein the thin film is epitaxially deposited on the intervening layer.

15 . The method of manufacture of claim 14 , further comprising removing the interviewing layer, releasing the thin film from the substrate.

16 . The method of claim 9 , wherein the epitaxial deposition is by atomic layer deposition.

17 . The method of claim 16 , wherein epitaxial deposition by atomic layer deposition comprises alternating exposures of CuAMD precursor and H 2 S precursor.

18 . The method of claim 16 , wherein the CuAMd precursor is dosed for 2 seconds.

19 . The method of claim 16 , wherein the H 2 S precursor is dosed for 0.1 s.

Assignees

• Uchicago Argonne Llc

Inventors

• Martinson Alex B
• Riha Shannon

Classifications

• H10P14/3466

  Crystal orientation · CPC title

• H10P14/3456

  Polycrystalline · CPC title

• H10P14/3436

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

• H10P14/2926

  Crystal orientations · CPC title

• H10P14/2911

  Arsenides · CPC title