Synthesis of vertically aligned metal oxide nanostructures

Patent metadata

Field	Value
Publication number	US-11208333-B2
Application number	US-201515506415-A
Country	US
Kind code	B2
Filing date	Aug 20, 2015
Priority date	Aug 26, 2014
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

Metal oxide nanostructure and methods of making metal oxide nanostructures are provided. The metal oxide nanostructures can be 1-dimensional nanostructures such as nanowires, nanofibers, or nanotubes. The metal oxide nanostructures can be doped or un-doped metal oxides. The metal oxide nanostructures can be deposited onto a variety of substrates. The deposition can be performed without high pressures and without the need for seed catalysts on the substrate. The deposition can be performed by laser ablation of a target including a metal oxide and, optionally, a dopant. In some embodiments zinc oxide nanostructures are deposited onto a substrate by pulsed laser deposition of a zinc oxide target using an excimer laser emitting UV radiation. The zinc oxide nanostructure can be doped with a rare earth metal such as gadolinium. The metal oxide nanostructures can be used in many devices including light-emitting diodes and solar cells.

First claim

We claim:

1. A method of making metal oxide nanostructures comprising:
providing a target comprising a metal oxide and a dopant;
ablating the target with a laser to create a plume containing the metal oxide and the dopant;
depositing the dopant from the plume onto the substrate to produce a homogeneous dopant interfacial nanolayer of uniform thickness directly on the substrate; and
depositing the metal oxide from the plume onto the dopant interfacial nanolayer to assist in forming homogeneous nucleation sites that stimulate growth of metal oxide nanostructures to produce homogeneous vertically aligned metal oxide nanostructures,
wherein the uniform thickness of the homogeneous dopant interfacial nanolayer is about 1 nm.

2. The method of claim 1 , wherein the target and the substrate are provided in chamber and the depositing step is performed within the chamber at a pressure of less than 500 mTorr.

3. The method of claim 1 , wherein the depositing step is performed under an oxygen atmosphere or under an inert atmosphere.

4. The method of claim 1 , wherein the depositing step is performed at a temperature of 500° C.-800° C.

5. The method of claim 1 , wherein the target is positioned below the substrate during the depositing step.

6. The method of claim 1 , wherein the distance between the substrate and the target is greater than 6 cm.

7. The method of claim 1 , wherein the laser is an excimer laser comprising a noble gas selected from the group consisting of argon, krypton, and xenon and a halogen gas selected from the group consisting of chloride and fluoride.

8. The method of claim 1 , wherein the substrate is free of seed catalysts prior to the deposition step.

9. The method of claim 1 , wherein the substrate is selected from the group consisting of a crystalline substrate, an amorphous substrate, and a plastic substrate.

10. The method of claim 1 , wherein the substrate is selected from the group consisting of a silicon substrate, a sapphire substrate, a quartz substrate, a glass substrate, a polyethylene terephthalate substrate, a polyimide substrate, and a ceramic substrate.

11. The method of claim 1 , wherein the substrate is a crystalline substrate having a lattice constant closely matched to a lattice constant of the metal oxide.

12. The method of claim 1 , wherein the nanostructures are selected from the group consisting of nanowires, nanorods, and nanotubes.

13. The method of claim 1 , wherein the metal oxide is a metal oxide semiconductor.

14. The method of claim 13 , wherein the metal oxide semiconductor comprises a metal selected from the group consisting of titanium, tin, niobium, tantalum, tungsten, and zinc.

15. The method of claim 1 , wherein the dopant is Gd.

16. The method of claim 1 , wherein the dopant is selected from the group consisting of alkaline earth metals and rare earth metals.

Assignees

• Univ King Abdullah Sci & Tech

Inventors

• Roqan Iman
• Flemban Tahani Hassan

Classifications

• H10P14/3464

  Nanotubes · CPC title

• H10P14/3426

  Oxides · CPC title

• H10P14/2921

  being crystalline insulating materials · CPC title

• H10P14/2905

  Silicon, silicon germanium or germanium · CPC title

• H10P14/22

  using physical deposition, e.g. vacuum deposition or sputtering · CPC title