Quantum Dot Organic Ligand for Low Turn-On Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current quantum dot-based light-emitting diodes (QD-LEDs) face inefficiencies and high turn-on voltages due to the long organic chains used in quantum dot organic ligands, which affect photoluminescence properties and increase light-up voltage.
Innovation Solution
Development of quantum dot organic ligands with a structure represented by Formula (1) or Formula (2), featuring a chelating group, a conjugated electron pair group, and an organic group, which form chelate linkages with the core-shell structure of quantum dots, improving electron and hole transport and reducing the length of organic chains to enhance efficiency and lower turn-on voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If long organic chains are used in quantum dot organic ligands, then the ligands can effectively bind to the quantum dot surface, but the turn-on voltage increases and efficiency decreases
Solution Approach 1:
The patent changes the key parameter of organic chain length from long to short (C1-C6 alkyl or alkenyl groups), fundamentally altering the ligand's physical properties. This parameter change reduces the organic chain length while maintaining binding effectiveness through the preserved chelating group (carboxyl, hydroxyl, or amino group) that forms strong coordinate bonds with metal atoms on the quantum dot surface.
Solution Approach 2:
The patent creates a composite ligand structure combining a short organic chain (alkyl or alkenyl group) with a functional chelating group (carboxyl, hydroxyl, or amino group). This composite structure integrates the advantages of both short chains (low turn-on voltage, high efficiency) and functional groups (strong binding capability), resolving the contradiction between binding effectiveness and energy consumption.
2Reliability
If long organic chains are used in quantum dot organic ligands, then the ligands provide sufficient steric protection, but the electron and hole transport is hindered
Solution Approach 1:
The patent changes the organic chain length parameter to a short range (C1-C6), which is sufficient to provide steric protection and stabilize the quantum dot structure while being short enough to allow efficient electron and hole transport between quantum dots, thereby improving charge carrier mobility and device productivity.
3Productivity
If the organic chain length is reduced, then the turn-on voltage decreases and efficiency improves, but the binding strength may be compromised
Solution Approach 1:
The patent designs a composite ligand structure where a short organic chain (providing steric protection and enabling efficient charge transport) is combined with a strong chelating group (carboxyl, hydroxyl, or amino group capable of forming coordinate bonds with metal atoms). This composite structure ensures that binding strength is maintained despite the reduced chain length, while simultaneously achieving low turn-on voltage and high device efficiency.
Solution Approach 2:
The patent applies local quality by concentrating the binding function in the chelating group (carboxyl, hydroxyl, or amino group) while keeping the organic chain short. The chelating group provides strong local binding capability through coordinate bonding with metal atoms on the quantum dot surface, compensating for the reduced overall ligand size and ensuring adequate binding strength.
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 new quantum dot organic ligands improve the efficiency of QD-LEDs by facilitating electron and hole transport, leading to higher external quantum efficiency, current efficiency, and power efficiency, while reducing the turn-on voltage, thus enhancing the performance of quantum dot-based light-emitting diodes.
Implementation Method 1
Through a carboxyl group of the organic ligand with a structure represented by Formula (1), a chelate linkage is formed between a shell of the core-shell structure of the quantum dot and the quantum dot organic ligand
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The present disclosure provides quantum dot organic ligand and preparation method thereof, quantum dot structure material, quantum-dot-containing layer, and quantum-dot-containing light emitting diode. The quantum dot organic ligand have the following structure R1- (R2) n-R3, wherein R1 is a chelating group capable of chelating with a metal; R2 is a group having a conjugated electron pair, and n is a positive integer; and R3 is organic group. The conjugated electron pair structure of R2 facilitates delocalization of electrons, which can improve the transport and conduction of electrons and/or holes, thereby improving the efficiency of quantum dots and lowering the turn-on voltage.