Tungsten(VI) Emitters for Cost-Effective OLED Phosphorescence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high cost of phosphorescent OLED technology, particularly due to the use of precious metals like iridium and platinum for phosphorescent emitters, presents a challenge for its adoption in low-end products, while tungsten, a more abundant and environmentally friendly metal, lacks reported strongly emissive complexes.
Innovation Solution
Development of novel tungsten(VI) emitters with specific chemical structures that facilitate intersystem crossing and phosphorescence, such as those depicted in Structures I, II, and III, which can be used in organic light-emitting diodes (OLEDs), reducing the need for expensive metals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If precious metals like iridium and platinum are used as phosphorescent emitters, then phosphorescence efficiency is improved, but manufacturing cost increases significantly
Solution Approach 1:
The patent replaces expensive precious metals (iridium, platinum) with tungsten, a more abundant and economically viable alternative. The tungsten(VI) complexes are designed to achieve phosphorescence without requiring rare metals, thereby reducing manufacturing costs while maintaining functional performance.
Solution Approach 2:
The patent modifies the chemical composition parameters by substituting the metal center from group 8/10 (Ir, Pt) to group 6 (W), specifically using tungsten(VI) oxidation state. This parameter change alters the electronic structure and spin-orbit coupling characteristics, enabling phosphorescence in a cost-effective manner.
2Ease of manufacture
If tungsten is used as an alternative to precious metals, then manufacturing cost is reduced, but emission efficiency is insufficient
Solution Approach 1:
The patent creates composite tungsten(VI) complexes by combining tungsten oxide clusters with organic ligands containing nitrogen and oxygen donor atoms. This composite structure synergistically enhances the spin-orbit coupling effect and stabilizes the phosphorescent state, achieving efficient emission from tungsten.
Solution Approach 2:
The patent optimizes the ligand field parameters around the tungsten(VI) center by selecting specific coordination geometries and donor atoms. This parameter optimization increases the spin-orbit coupling constant and promotes efficient intersystem crossing, thereby improving phosphorescence quantum yield.
3Reliability
If d-d ligand field excited states are present in tungsten(VI) complexes, then non-radiative decay increases, but these states are absent in the designed complexes
Solution Approach 1:
The patent extracts or eliminates the problematic d-d ligand field excited states from the tungsten(VI) complex energy level scheme by designing ligands that create a large energy gap between the ground state and d-d excited states. This prevents non-radiative decay pathways and enhances emission stability.
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 use of tungsten(VI) emitters in OLEDs offers a cost-effective and environmentally benign alternative, achieving efficient energy transfer and emission, as demonstrated by the examples of synthesized compounds and their performance in OLED devices.
Implementation Method 1
it should therefore possess strong heavy atom effect that facilitates intersystem crossing and phosphorescence
Implementation Method 2
As phosphorescent OLED converts all singlet and triplet energy electrical energy to light energy
Implementation Method 3
achieving efficient energy transfer and emission
Data Source
AI summary
Described are to tungsten(VI) emitters. These materials can be used to fabricate OLEDs.