Germanium Heterocycles With AIE for Solid-State Fluorescence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing luminescent materials face aggregation-caused quenching issues, leading to decreased sensitivity and reliability in solid-state applications, particularly in electroluminescent devices, due to interactions between neighboring fluorophores that form delocalized excitons or excimers, necessitating low fluorophore concentrations to mitigate this effect.
Innovation Solution
Development of luminescent compounds with a germanium ring core, such as substituted germoles, germafluorenes, germa-fluoresceins, and germapins, which exhibit high fluorescence quantum yields in the solid state through aggregation-induced emission (AIE) and restricted intramolecular rotation (RIR), allowing for efficient light emission even in aggregated forms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high concentrations of fluorophore molecules are used in solid state applications, then the sensitivity and reliability of fluorescent signal should be improved, but aggregation-caused quenching occurs leading to decreased fluorescence quantum yield
Solution Approach 1:
The patent inverts the conventional approach by designing luminophors where aggregation induces emission rather than quenching. The AIE-active germanium compounds exhibit enhanced fluorescence in aggregated solid state forms compared to dilute solutions, directly reversing the typical ACQ behavior and enabling high concentration use without signal loss
Solution Approach 2:
The patent changes the photophysical parameters of the luminophor molecules by incorporating germanium centers with specific coordination geometries and electronic structures. This modifies the molecular properties to prevent non-radiative decay pathways in aggregated states, transforming the material from ACQ-prone to AIE-active with quantum yields exceeding 60% in solid state
2Loss of energy
If low concentrations of fluorophore molecules are used to mitigate aggregation-caused quenching, then fluorescence quantum yield is maintained, but sensitivity and reliability of fluorescent signal decrease
Solution Approach 1:
The patent reverses the concentration-fluorescence relationship by creating materials where aggregated high-concentration states produce stronger signals than dilute states. This inversion eliminates the need for low concentration usage and enables sensitive detection at high material loads
Solution Approach 2:
The patent creates composite luminescent systems combining germanium-centered luminophors with matrix materials or other components that enhance the AIE effect. These composite structures provide both high quantum yield and enhanced sensitivity through synergistic interactions between components
3Ease of manufacture
If conventional luminescent materials are used in solid state form, then device fabrication is simplified, but aggregation-caused quenching renders them ineffective for electroluminescent devices
Solution Approach 1:
The patent changes the fundamental photophysical parameters of solid state luminescent materials by introducing germanium centers with specific electronic configurations. This transformation enables the materials to maintain high fluorescence quantum yields (>60%) in solid state forms, making them suitable for electroluminescent device applications
Solution Approach 2:
The patent introduces localized germanium-centered luminophor units with specific molecular structures and electronic properties into the solid state matrix. These localized AIE-active units maintain their high quantum yield characteristics even in the condensed phase, providing reliable electroluminescent performance while preserving solid state fabrication advantages
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
These compounds provide intense fluorescence in the solid state, enhancing sensitivity and reliability for applications in light-emitting devices and sensors, with quantum yields up to 65 times higher than in solution, suitable for electron-transport layers and chemical or biological sensing.
Implementation Method 1
exhibit high fluorescence quantum yields in the solid state through aggregation-induced emission (AIE)
Implementation Method 2
aggregation-induced emission (AIE) and restricted intramolecular rotation (RIR), allowing for efficient light emission even in aggregated forms
Implementation Method 3
provide intense fluorescence in the solid state, enhancing sensitivity and reliability for applications in light-emitting devices and sensors, with quantum yields up to 65 times higher than in solution
Data Source
AI summary
The present disclosure provides a new series of compounds exhibiting high fluorescence quantum yields in the solid state. In one embodiment, the compounds include a series of 2,3,4,5-tetraphenylgermoles with the same or different 1,1-substituents. In another embodiment, substituted germafluorenes, germa-fluoresceins/rhodamines, and germapins are described. These germanium heterocycles possess ideal photophysical and thermostability properties, which makes them excellent candidates for chemical or biological sensors, host materials for electroluminescent devices and solar cells, and emissive and/or electron-transport layer components in organic light emitting diode devices.