OLED Host-Dopant System for High Efficiency and Long Lifespan
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Solution Overview
Problem
There is a need for an organic light emitting diode (OLED) that can be stably driven at a lower voltage and exhibits high efficiency and longevity, which current OLEDs using various compounds in light emitting layers have not adequately addressed.
Innovation Solution
The OLED employs specific boron compounds and anthracene compounds as a dopant and host material, respectively, in the light-emitting layer, optimizing the structure and composition to enhance luminous efficiency and lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional compounds are used in light emitting layers, then OLED can be manufactured with standard materials, but the OLED exhibits insufficient luminous efficiency and short lifespan
Solution Approach 1:
The patent changes the chemical parameters of the light emitting layer by selecting specific host compounds (triphenylamine derivative, triphenidine derivative, or carbazole derivative) and specific dopant compounds (boron compound with defined molecular structure). This parameter optimization resolves the contradiction by achieving both high luminous efficiency (39) and long lifespan (27) through improved molecular characteristics including appropriate HOMO-LUMO energy levels and enhanced stability
Solution Approach 2:
The patent employs a composite material system consisting of a host compound and a dopant compound in the light emitting layer. The host compound provides the basic luminescence framework while the boron-containing dopant compound enhances efficiency and stability. This composite approach simultaneously improves luminous efficiency and lifespan by leveraging the complementary properties of both materials
2Illumination intensity
If higher driving voltage is applied to improve luminous efficiency, then light emission intensity increases, but device stability and lifespan decrease
Solution Approach 1:
The patent optimizes the energy level parameters of the light emitting layer materials, specifically designing the host and dopant compounds to have appropriate HOMO-LUMO energy levels that enable efficient charge injection and recombination at lower voltages. This parameter optimization allows the OLED to achieve high luminous efficiency without requiring high driving voltages, thereby maintaining device stability and extending lifespan
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 these specific compounds results in an OLED with improved high emission yield and longevity compared to conventional OLEDs, allowing for stable operation at lower driving voltages.
Implementation Method 1
a host-dopant system may be used as a luminescent material so as to increase the color purity and the luminous efficiency through energy transfer
Implementation Method 2
application of a voltage between the two electrodes injects a hole from the anode and an electron from the cathode to the organic layer. In the luminescent zone, the hole and the electron recombine to produce an exciton. When the exciton returns to the ground state from the excited state, the molecule of the organic layer emits light.
Data Source
AI summary
The present invention relates to an organic light-emitting device comprising, in a light-emitting layer thereof: a compound represented by [chemical formula A]; and a compound represented by any one of [chemical formula D-6] and [chemical formula D-7], wherein [chemical formula A], [chemical formula D-6], and [chemical formula D-7] are as described in the detailed description of the invention.