Plasmonic Resonator Display Using Phase Change Material

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional color displays rely on additive techniques, which may not efficiently manage power consumption and color output, especially in applications requiring low energy usage and high reflectance.

Innovation Solution

A display using pixels with a plasmonic resonator structure comprising metallic material elements and a phase change material, where the phase change material switches between states to control light absorption and reflectance, allowing for subtractive color generation with low power consumption by using GeTe or Ge2Sb2Te5, and a dielectric layer for environmental protection and electric field application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If additive color techniques are used in conventional displays, then color output can be achieved, but power consumption increases and reflectance efficiency decreases

Engineering Contradiction:

Improvepower consumptionVSAvoidreflectance efficiency

Core Design Contradiction:

Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The patent inverts the conventional additive color approach by using subtractive color techniques. Instead of generating light through emission, the display absorbs specific wavelengths and reflects others to produce color. The plasmonic resonator structure is designed to strongly absorb selected wavelengths in the crystalline state while maintaining high reflectance in the amorphous state, achieving color output with lower power consumption and higher reflectance efficiency.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent utilizes phase transitions of the phase change material (PCM) between amorphous and crystalline states to control optical properties. The PCM's phase change alters the plasmonic resonator's coupling strength, switching between high absorption (crystalline) and high reflectance (amorphous) states. This enables binary color control with minimal power input, as only phase transition energy is required rather than continuous power for light emission.

Inventive Principle:

Principle #36Phase transitions

2Illumination intensity

If phase change material is used to control light absorption, then color output can be achieved, but device complexity increases

Engineering Contradiction:

Improvecolor outputVSAvoidpixel structure

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The patent merges multiple functions into the plasmonic resonator structure: the metallic elements provide both structural support and optical resonance functionality, the phase change material serves as both the switching mechanism and the optical absorption layer, and the dielectric layer provides both environmental protection and electrical insulation. This integration reduces the number of separate components needed while achieving complex color control functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent employs composite material structures combining metallic elements (for plasmonic resonance), phase change material (for state switching), and dielectric materials (for protection and insulation). This composite approach enables the plasmonic resonator to exhibit tunable optical properties through phase change, achieving color control without requiring complex mechanical or electronic mechanisms.

Inventive Principle:

Principle #40Composite materials

3Illumination intensity

If strong electric field coupling is achieved in crystalline phase, then light absorption increases, but response time may increase

Engineering Contradiction:

Improvelight absorptionVSAvoidresponse time

Core Design Contradiction:

Illumination intensityVSSpeed

Solution Approach 1:

The patent employs periodic or pulsed electrical excitation to induce phase changes in the PCM. Rather than continuous heating, brief high-power pulses are applied to trigger the amorphous-to-crystalline transition, followed by relaxation periods. This periodic action achieves the desired phase change and optical state switching with minimal energy input and fast response times, as the PCM transitions rapidly during each pulse cycle.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS11567389B2Display

Publication Date: 2023.01.31 UNIV OF EXETER

AI summary

A display is described which comprises a plurality of pixels (12), wherein each pixel (12) comprises a plasmonic resonator (26) including first and second metallic material elements (16, 22) and incorporating a layer (18) of a phase change material, the plasmonic resonator (26) being arranged such that in one material state of the phase change material (18) the electric field coupling between the second metallic material element (22) and the phase change material layer (18) is strong and so strong absorption of selected wavelengths of the incident light occurs, whereas in another state of the phase change material (18) the electric field coupling between the metallic material elements (16, 22) and the phase change material layer (18), and between the first and second metallic material elements (16, 22) is weak and so re-radiation of incident light occurs, the pixel (12) being of high reflectance.