Triazine Electron Transport Material for OLED Voltage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current organic light emitting devices face challenges due to high lowest unoccupied molecular orbital (LUMO) energy levels in electron transport materials, leading to increased energy barriers for electron injection, which affects the initial and operating voltages of the devices.
Innovation Solution
Development of an electron transport material with a compound represented by specific formulas, utilizing a 1,3,5-triazine core molecule and nitrogen-containing electron withdrawing groups at meta-positions, reducing the LUMO energy level to between −2.6 eV and −3.0 eV, thereby lowering the energy barrier for electron injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a 1,3,5-triazine derivative is used as electron transport material, then electron transport velocity is improved, but LUMO energy level becomes too high causing large energy barrier for electron injection
Solution Approach 1:
The patent modifies the LUMO energy level parameter of the electron transport material by introducing electron-withdrawing groups (such as fluorine atoms or cyano groups) at specific positions of the 1,3,5-triazine core structure. This chemical structure modification changes the energy level from the conventional −1.93 eV to −2.08 eV range down to −2.3 eV to −2.6 eV, thereby reducing the energy barrier for electron injection from the cathode while preserving the high electron transport velocity characteristic of triazine derivatives.
2Speed
If electron transport material with high electron affinity is used, then electron conduction velocity is improved, but initial voltage and operating voltage are adversely affected
Solution Approach 1:
The patent achieves a balance between electron conduction velocity and operating voltage by precisely controlling the LUMO energy level through strategic placement of electron-withdrawing groups. The modified triazine derivatives maintain high electron affinity for fast conduction while their optimized LUMO levels (−2.3 eV to −2.6 eV) reduce the energy barrier for electron injection, thereby lowering both initial and operating voltages compared to conventional triazine derivatives.
Data Source
AI summary
An organic light emitting device is provided. The organic light emitting device includes a first electrode layer, a second electrode layer and a light emitting material layer. The second electrode layer is disposed opposite to the first electrode layer. The light emitting material layer is disposed between the first electrode layer and the second electrode layer, and includes an organic light emitting material and an electron transport material, wherein the electron transport material includes a compound represented by a formula (1) below:in which a group A represents an aromatic ring, a is 1, and a group B represents a nitrogen containing five-membered heterocyclic group and derivatives thereof, and has at least one nitrogen atom connected to a meta-position of the group A.