Organic EL Element Near-Infrared Emission Optimization
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Solution Overview
Problem
Conventional organic electro-luminescent elements for bioinstrumentation have poor biocompatibility and design flexibility, and those emitting light in the near-infrared range suffer from low luminous efficiency and unwanted visible light emission, which affects the reliability of biological sensing.
Innovation Solution
An organic electro-luminescent element with a luminescent layer comprising a host material, a delayed fluorescent material, and a luminescent material, where the energy level relationships between these materials are optimized to achieve peak emission in the near-infrared range with minimal visible light emission, enhancing both electrical properties and device life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional solid-state luminescent elements are used, then device reliability is improved, but biocompatibility and design flexibility deteriorate
Solution Approach 1:
The patent changes the material parameters from inorganic semiconductors to organic electroluminescent materials, enabling flexible substrate deposition while achieving near-infrared emission. This parameter change allows the device to be manufactured on plastic substrates, improving biocompatibility and design flexibility without sacrificing reliability
Solution Approach 2:
The patent uses composite organic material systems comprising host materials, delayed fluorescent materials, and luminescent materials. This composite approach enables tuning of emission characteristics to achieve near-infrared peak emission while maintaining device reliability through synergistic material interactions
2Adaptability or versatility
If organic EL elements are used to achieve near-infrared emission, then biocompatibility and design freedom are improved, but luminous efficiency deteriorates
Solution Approach 1:
The patent optimizes energy level parameters of the organic materials to achieve efficient near-infrared emission. By carefully selecting host materials, delayed fluorescent materials, and luminescent materials with appropriate HOMO-LUMO energy level differences, the system achieves high luminous efficiency in the near-infrared range while maintaining biocompatibility and design freedom
Solution Approach 2:
The patent applies local quality optimization by using delayed fluorescent materials as assistant dopants in specific regions of the luminescent layer. This localized approach improves luminous efficiency at the near-infrared peak wavelength without compromising the overall biocompatibility and design flexibility of the organic EL element
3Measurement precision
If organic EL elements emit light in near-infrared range, then biological sensing capability is improved, but visible light emission produces noise that deteriorates sensing reliability
Solution Approach 1:
The patent achieves wavelength-selective emission by carefully designing the energy levels of the organic materials. The delayed fluorescent material and luminescent material are selected to emit predominantly in the near-infrared range (700-2500 nm) while suppressing visible light emission. This color control eliminates noise in biological sensing applications by ensuring that only the desired near-infrared wavelengths are emitted
Solution Approach 2:
The patent optimizes the energy level parameters (HOMO and LUMO levels) of the organic materials to control the emission spectrum. By adjusting these parameters, the system achieves peak emission in the near-infrared range while minimizing visible light emission, thereby improving biological sensing reliability by reducing noise
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 solution provides an organic electro-luminescent element that emits light efficiently in the near-infrared range with low luminescent intensity in the visible light range, improving the reliability and longevity of bioinstrumentation devices by minimizing noise from visible light emission.
Implementation Method 1
The luminescent layer comprises a host material, a delayed fluorescent material and a luminescent material
Implementation Method 2
the delayed fluorescent material and the luminescent material may satisfy the relationships (1) to (4) shown below: ΔHOMO+ΔLUMO≤0.6 eV; |ΔHOMO|≤0.4 eV; |ΔLUMO|≤0.4 eV
Implementation Method 3
An organic electro-luminescent element with a luminescent layer comprising a host material, a delayed fluorescent material, and a luminescent material
Data Source
AI summary
An organic EL element having a luminescence peak in a near-infrared range comprises a positive electrode, a negative electrode, and at least one organic layer including a luminescent layer located between the positive electrode and the negative electrode. The luminescent layer comprises a host material, a delayed fluorescent material and a luminescent material. The LUMO and HOMO energy levels of the delayed fluorescent material and the luminescent material, the absorption spectrum of the luminescent material, and the emission spectrum of the delayed fluorescent material satisfy predetermined relationships.