Electric field-tunable IR devices with very large modulation of refractive index and methods to fabricate them

Patent metadata

Field	Value
Publication number	US-11988907-B1
Application number	US-202117212611-A
Country	US
Kind code	B1
Filing date	Mar 25, 2021
Priority date	May 20, 2020
Publication date	May 21, 2024
Grant date	May 21, 2024

Abstract

An electric field-controlled refractive index tunable device includes a phase change correlated transition metal oxide layer, and E-field responsive charge dopants. The E-field responsive charge dopants either accumulate in the phase change correlated transition metal oxide layer or are depleted from the phase change correlated transition metal oxide layer in response to an E-field applied to the phase change correlated transition metal oxide layer.

First claim

What is claimed is:

1. An electric field-controlled refractive index tunable device comprising:
a phase change correlated transition metal oxide layer; and
E-field responsive charge dopants, wherein the E-field responsive charge dopants either accumulate in the phase change correlated transition metal oxide layer or are depleted from the phase change correlated transition metal oxide layer in response to an E-field applied to the phase change correlated transition metal oxide layer;

wherein the phase change correlated transition metal oxide layer has an optical extinction coefficient k of less than 0.01.

2. The electric field-controlled refractive index tunable device of claim 1 wherein the phase change correlated transition metal oxide layer comprises NdNiO 3 , SmNiO 3 , PrNiO3, EuNiO 3 , or GdNiO 3 , or any combination of NdNiO 3 , SmNiO 3 , PrNiO3, EuNiO 3 , and GdNiO 3 .

3. An electric field-controlled refractive index tunable device comprising:
a phase change correlated transition metal oxide layer; and
E-field responsive charge dopants, wherein the E-field responsive charge dopants either accumulate in the phase change correlated transition metal oxide layer or are depleted from the phase change correlated transition metal oxide layer in response to an E-field applied to the phase change correlated transition metal oxide layer;

wherein the E-field responsive charge dopants comprise hydrogen dopants.

4. An electric field-controlled refractive index tunable device comprising:
a phase change correlated transition metal oxide layer; and
E-field responsive charge dopants, wherein the E-field responsive charge dopants either accumulate in the phase change correlated transition metal oxide layer or are depleted from the phase change correlated transition metal oxide layer in response to an E-field applied to the phase change correlated transition metal oxide layer;

the device further comprising either:
a substrate;
a bottom electrode on the substrate;
a diffusion barrier layer on the bottom electrode, wherein the phase change correlated transition metal oxide layer is on the diffusion barrier layer; and
an optically transparent top electrode on the phase change correlated transition metal oxide layer; or
a substrate;
a diffusion barrier on the substrate;
a bottom electrode on the diffusion barrier, wherein the phase change correlated transition metal oxide (PCMO) layer is on the bottom electrode; and
an optically transparent top electrode on the phase change correlated transition metal oxide (PCMO) layer.

5. The electric field-controlled refractive index tunable device of claim 4 , comprising a substrate;
a bottom electrode on the substrate;
a diffusion barrier layer on the bottom electrode, wherein the phase change correlated transition metal oxide layer is on the diffusion barrier layer; and
an optically transparent top electrode on the phase change correlated transition metal oxide layer:
wherein the optically transparent top electrode comprises:
a catalytic transition metal comprising Pt, Pd, or Ni;
an ultrathin catalytic transition metallic film comprising Pt, Pd, or Ni;
a graphene layer; or
a LaNiO 3 -based layer;

wherein the diffusion barrier layer comprises:
a graphene layer; or
a nitride-based dielectric thin film; or
an oxide-based dielectric thin film and

wherein the substrate comprises:
a semiconductor, Si, GaAs, SiC, an electrically insulating wafer, SiO 2 , Si 3 N 4 , LaAlO 3 , BaTiO 3 , SrTiO 3 , glass, a mechanically rigid substrate, or a flexible substrate, such as polyethylene terephthalate (PET).

6. The electric field-controlled refractive index tunable device of claim 4 , comprising a substrate;
a bottom electrode on the substrate;
a diffusion barrier layer on the bottom electrode, wherein the phase change correlated transition metal oxide layer is on the diffusion barrier layer; and
an optically transparent top electrode on the phase change correlated transition metal oxide layer; wherein:
a positive E-field between the optically transparent top electrode and the bottom electrode causes positively charged or electron accepting E-field responsive charge dopants to accumulate in the phase change correlated transition metal oxide layer, and causes the refractive index of the phase change correlated transition metal oxide layer to be substantially n + n; and
a negative E-field between the optically transparent top electrode and the bottom electrode causes positively charged or electron accepting E-field responsive charge dopants to be depleted from the phase change correlated transition metal oxide layer and to move to the optically transparent top electrode, and causes the refractive index of the phase change correlated transition metal oxide layer to be substantially n ;
wherein n is a refractive index for pristine and undoped phase change correlated transition metal oxide layer; and
wherein n + n is a refractive index for phase change correlated transition metal oxide layer having E-field responsive charge dopants.

7. The electric field-controlled refractive index tunable device of claim 4 , comprising a substrate;
a bottom electrode on the substrate;
a diffusion barrier layer on the bottom electrode, wherein the phase change correlated transition metal oxide layer is on the diffusion barrier layer; and
an optically transparent top electrode on the phase change correlated transition metal oxide layer; wherein:
a negative E-field between the optically transparent top electrode and the bottom electrode causes negatively charged or electron donating E-field responsive charge dopants to accumulate in the phase change correlated transition metal oxide layer, and causes the refractive index of the phase change correlated transition metal oxide layer to be substantially n + n; and
a positive E-field between the optically transparent top electrode and the bottom electrode causes negatively charged or electron donating E-field responsive charge dopants to be depleted from the phase change correlated transition metal oxide layer and to move to the optically transparent top electrode, and causes the refractive index of the phase change correlated transition metal oxide layer to be substantially n ;
wherein n is a refractive index for pristine and undoped phase change correlated transition metal oxide layer; and
wherein n + n is a refractive index for phase change correlated transition metal oxide layer having E-field responsive charge dopants.

8. The electric field-controlled refractive index tunable device of claim 4 , comprising a substrate;
a bottom electrode on the substrate;
a diffusion barrier layer on the bottom electrode, wherein the phase change correlated transition metal oxide layer is on the diffusion barrier layer; and
an optically transparent top electrode on the phase change correlated transition metal oxide layer:
wherein a refractive index of the phase change correlated transition metal oxide film layer may be set to a desired value between a range from n to n + n by tuning the E-field between the optically transparent top electrode and the bottom electrode;
wherein n is a refractive index for pristine and undoped phase change correlated transition metal oxide layer; and
wherein n + n is a refractive index for phase change correlated transition metal oxide layer having E-field responsive charge dopants.

9. The electric field-controlled refractive index tunable device of claim 4 , comprising a substrate;
a bottom electrode on the substrate;
a diffusion barrier layer on the bottom electrode, wherein the phase change correlated transition metal oxide layer is on the diffusion barrier layer; and
an optically tran

Assignees

• Hrl Lab Llc

Inventors

• Son Kyung-Ah
• Moon Jeong-Sun
• Seo Hwa Chang
• Kremer Richard M
• Quarfoth Ryan G

Classifications

• G02F1/19

  based on variable-reflection or variable-refraction elements not provided for in groups G02F1/015 - G02F1/169 · CPC title

• G02F1/0316 Primary

  Electrodes · CPC title

• G02F1/0333

  addressed by a beam of charged particles (G02F1/05 takes precedence) · CPC title

• G02F2203/11

  involving infrared radiation · CPC title