D-A-D Infrared Absorber for Low-Light Organic Sensor Sensitivity

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Solution Overview

Problem

Existing photoelectric devices and sensors struggle with inadequate infrared light absorption characteristics, particularly in low-illumination environments, limiting their sensitivity and performance.

Innovation Solution

Development of an infrared absorber with a donor-acceptor-donor (D-A-D) structure, utilizing electron-donating and electron-accepting heteroaromatic rings linked through specific rings, enhancing charge transfer and absorption in the infrared region, with improved thermal stability for deposition processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional photoelectric devices are used, then device structure is simple, but infrared light absorption characteristics are inadequate

Engineering Contradiction:

Improveinfrared light absorption characteristicsVSAvoidmolecular structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies composite materials by combining electron-donating heteroaromatic rings (such as triphen胺 or carbazole) with electron-accepting heteroaromatic rings (such as benzobisthiadiazole or benzothiadiazole) to create a donor-acceptor-donor (D-A-D) structured infrared absorber. This composite molecular structure enables strong infrared light absorption through intramolecular charge transfer, resolving the contradiction between maintaining simple device structure and achieving adequate infrared absorption characteristics.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent employs parameter changes by modifying the HOMO-LUMO energy gap of the absorber material through careful selection of electron-donating and electron-accepting groups. By adjusting the energy level parameters of the molecular components, the absorption peak is tuned to the infrared region (750-3000 nm) while maintaining thermal stability for deposition processes, thus improving infrared absorption without excessive structural complexity.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If infrared absorber with D-A-D structure is used, then infrared absorption characteristics are improved, but manufacturing process complexity increases

Engineering Contradiction:

Improveinfrared absorption characteristicsVSAvoiddeposition process complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent addresses manufacturing complexity by optimizing the thermal properties of the D-A-D structured absorber material. The molecular design ensures sufficient thermal stability to enable conventional deposition processes (such as vacuum thermal evaporation or solution processing) while maintaining the infrared absorption characteristics. This parameter optimization allows the complex molecular structure to be manufactured using standard fabrication techniques.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If absorber material with extended conjugation is used, then infrared absorption is enhanced, but thermal stability for deposition decreases

Engineering Contradiction:

Improveinfrared absorptionVSAvoidthermal stability

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent resolves the thermal stability issue by using composite heteroaromatic structures with rigid frameworks. The combination of electron-donating rings (such as carbazole or triphen胺) and electron-accepting rings (such as benzobisthiadiazole) creates a D-A-D structure where the rigid heteroaromatic cores provide thermal stability during deposition, while the extended π-conjugation between these stable units enables strong infrared absorption through charge transfer transitions.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by designing specific regions of the molecule with different functions: the heteroaromatic ring cores provide thermal stability and structural rigidity for deposition processing, while the conjugated linkers between these cores provide the extended electron delocalization needed for infrared absorption. This spatial separation of functions allows both thermal stability and infrared absorption to coexist.

Inventive Principle:

Principle #3Local quality

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 infrared absorber exhibits strong light absorption properties in the infrared region, improving the performance of photoelectric devices and organic sensors, particularly in low-illumination conditions.

Implementation Method 1

utilizing electron-donating and electron-accepting heteroaromatic rings linked through specific rings, enhancing charge transfer and absorption in the infrared region

Methodology Applied

Scientific EffectCharge transfer:

Implementation Method 2

The infrared absorber exhibits strong light absorption properties in the infrared region

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentEP3858839B1Infrared absorbers, infrared absorbing/blocking films, photoelectric devices, organic sensors, and electronic devices

Publication Date: 2026.04.15 SAMSUNG ELECTRONICS CO LTD

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AI summary

An infrared absorber includes a compound represented by Chemical Formula 1. An infrared absorbing/blocking film, a photoelectric device, an organic sensor, and an electronic device may include the infrared absorber. In Chemical Formula 1, Ar, X1, X2, Y1, Y2, R1, R2, R11, R12, R13, and R14 are the same as defined in the detailed description.