OLED Electrochromic Microcavities for Color Temperature Control

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Solution Overview

Problem

Conventional organic light emitting devices have limited color temperature adjustment capabilities and require significant voltage changes to achieve large color temperature adjustments, leading to undesirable changes in light intensity.

Innovation Solution

An organic light emitting device with a first electrode, an organic layer, a second electrode, an electrochromic layer, and a third electrode, along with tunable microcavities, allows for independent adjustment of color temperature through electrical potential differences between these electrodes, enhancing the color temperature adjustment range without affecting light intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If significant voltage changes are applied to achieve large color temperature adjustments in conventional OLEDs, then color temperature adjustment range is improved, but light intensity changes undesirably

Engineering Contradiction:
Improvecolor temperatureVSAvoidlight intensity
Core Design Contradiction:
TemperatureVSIllumination intensity

Solution Approach 1:

The device divides the color temperature control function into two independent segments: the organic light emitting layer controls light intensity through voltage, while the electrochromic layer controls color temperature through voltage. This segmentation allows independent optimization of each parameter without mutual interference, resolving the contradiction between color temperature adjustment range and light intensity stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrochromic layer acts as an intermediary between the voltage input and the final light output. It receives voltage signals to adjust color temperature while the organic light emitting layer simultaneously controls light intensity. The microcavity structure further mediates the optical output by enhancing specific wavelengths, enabling precise color temperature control independent of overall brightness.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If conventional OLED structures are used, then device simplicity is maintained, but color temperature adjustment capability is limited

Engineering Contradiction:
Improvecolor temperature adjustment capabilityVSAvoiddevice structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The electrochromic layer serves multiple functions: it adjusts color temperature, acts as a charge transport layer, and provides optical filtering. The microcavity structure simultaneously enhances light extraction efficiency and enables wavelength-selective emission. This multi-functionality approach increases color temperature adjustment capability while minimizing the addition of separate components, thus limiting the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The device uses composite material structures: the electrochromic layer is integrated with charge transport materials, and the microcavity incorporates dielectric layers with specific refractive indices. These composite structures enable color temperature tuning through material property changes rather than requiring separate mechanical adjustment components, maintaining relative structural simplicity while enhancing functionality.

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The device achieves a broader range of color temperature adjustments with minimal changes in light intensity by utilizing electrochromic layers and tunable microcavities, enabling precise control over the emitted light's color temperature.

Implementation Method 1

an electrochromic layer between the first electrode and the organic layer

Methodology Applied
Scientific EffectElectrochromism: Electrochromism

Implementation Method 2

a first microcavity in a first region corresponding to the third electrode and a second microcavity in a second region

Methodology Applied
Scientific EffectOptical interference: Interference

Data Source

PatentEP3622567B1Organic light emitting device, display apparatus, method of controlling color temperature of light emitted from organic light emitting device, and method of fabricating organic light emitting device
Publication Date: 2026.01.28 BOE TECHNOLOGY GROUP CO LTD
  • EP3622567B1 patent drawingFigure 1A
  • EP3622567B1 patent drawingFigure 1B
  • EP3622567B1 patent drawingFigure 2

AI summary

An organic light emitting device includes a first electrode (2); an organic layer (6) on the first electrode (2), the organic layer (6) having an organic light emitting layer; a second electrode (10) on a side of the organic layer (6) distal to the first electrode (2); an electrochromic layer (3) between the first electrode (2) and the organic layer (6); and a third electrode (4) between the electrochromic layer (3) and the organic layer (6).