Local doping of two-dimensional materials

Patent metadata

Field	Value
Publication number	US-9449851-B2
Application number	US-201514833407-A
Country	US
Kind code	B2
Filing date	Aug 24, 2015
Priority date	Aug 29, 2014
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

This disclosure provides systems, methods, and apparatus related to locally doping two-dimensional (2D) materials. In one aspect, an assembly including a substrate, a first insulator disposed on the substrate, a second insulator disposed on the first insulator, and a 2D material disposed on the second insulator is formed. A first voltage is applied between the 2D material and the substrate. With the first voltage applied between the 2D material and the substrate, a second voltage is applied between the 2D material and a probe positioned proximate the 2D material. The second voltage between the 2D material and the probe is removed. The first voltage between the 2D material and the substrate is removed. A portion of the 2D material proximate the probe when the second voltage was applied has a different electron density compared to a remainder of the 2D material.

First claim

What is claimed is:

1. A method comprising:
(a) forming an assembly including a substrate, a first insulator disposed on the substrate, a second insulator disposed on the first insulator, and a two-dimensional (2D) material disposed on the second insulator;
(b) applying a first voltage between the 2D material and the substrate;
(c) with the first voltage applied between the 2D material and the substrate, applying a second voltage between the 2D material and a probe positioned proximate the 2D material;
(d) removing the second voltage between the 2D material and the probe; and
(e) removing the first voltage between the 2D material and the substrate, a portion of the 2D material proximate the probe in operation (c) having a different electron density compared to a remainder of the 2D material.

2. The method of claim 1 , wherein the 2D material comprise about 10 monolayers of material or less.

3. The method of claim 1 , wherein the 2D material comprises graphene.

4. The method of claim 1 , wherein the 2D material is selected from a group consisting of molybdenum disulfide, molybdenum diselenide, tungsten disulfide, and tungsten diselenide.

5. The method of claim 1 , wherein the probe is positioned about 10 nanometers or less from the 2D material in operation (c).

6. The method of claim 1 , wherein the second voltage applied between the 2D material and the probe in operation (c) is about −100 volts to +100 volts.

7. The method of claim 1 , wherein the second voltage applied between the 2D material and the probe in operation (c) is about +5 volts or higher.

8. The method of claim 1 , wherein the second voltage applied between the 2D material and the probe in operation (c) is about −3 volts or lower.

9. The method of claim 1 , wherein the second voltage applied between the 2D material and the probe in operation (c) is applied for about 0.1 seconds to 5 minutes.

10. The method of claim 1 , wherein the first voltage applied between the 2D material and the substrate in operation (b) is about −150 volts to about +150 volts.

11. The method of claim 1 , wherein the first insulator comprises a material selected from a group consisting of silicon oxide, hafnium oxide, and aluminum oxide, wherein the second insulator comprises a material selected from a group consisting of boron nitride and a silicate mineral, and wherein the substrate comprises a material selected from a group consisting of a doped semiconductor, a layered semimetal, and a metal.

12. The method of claim 1 , wherein the first insulator has a greater band gap than the second insulator.

13. The method of claim 1 , wherein the probe comprises a conductive material.

14. The method of claim 1 , wherein the probe comprises a metal wire or a carbon nanotube.

15. The method of claim 1 , wherein the probe comprises a conductive substrate and a pattern disposed on a surface the conductive substrate comprising a conductive material.

16. The method of claim 1 , wherein the first insulator is about 10 nanometers to 500 nanometers thick.

17. The method of claim 1 , wherein the second insulator is about 5 nanometers to 300 nanometers thick.

18. The method of claim 1 , wherein the substrate has a thickness of about 50 nanometers or greater.

Assignees

• Wong Dillon
• Velasco Jr Jairo
• Ju long
• Kahn Salman
• Lee Juwon
• Germany Chad E
• Zettl Alexander K
• Wang Feng
• Crommie Michael F
• Univ California

Inventors

• Wong Dillon
• Velasco Jr Jairo
• Ju long
• Kahn Salman
• Lee Juwon
• Germany Chad E
• Zettl Alexander K
• Wang Feng
• Crommie Michael F

Classifications

• H10P14/3436

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

• H10P14/3406

  Carbon, e.g. diamond-like carbon · CPC title

• H10P14/3248

  consisting of two layers · CPC title

• H10P14/3238

  being insulating materials · CPC title

• H10P14/2905

  Silicon, silicon germanium or germanium · CPC title