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Selenium-Containing Multi-Resonance Thermally Activated Delayed Fluorescence Host Material for Green and Red
Hyukmin Kwon1, Seokwoo Kang1, Sangwook Park1
1Integrated Engineering, Department of Chemical Engineering, Kyung Hee University, Yongin-si 17104, Republic of Korea.
Materials (Basel, Switzerland)
|May 14, 2025
Summary
A novel selenium-based host material enhances phosphorescent organic light-emitting diodes (PhOLEDs) by improving efficiency and reducing roll-off. This molecular design accelerates the reverse intersystem crossing process for better performance.
Area of Science:
- Materials Science
- Organic Electronics
- Photophysics
Background:
- Phosphorescent organic light-emitting diodes (PhOLEDs) are crucial for efficient lighting and displays.
- Efficiency roll-off and limited operational stability remain challenges in PhOLED technology.
- Multi-resonance thermally activated delayed fluorescence (MR-TADF) materials offer a pathway to high efficiency.
Purpose of the Study:
- To design and synthesize a novel selenium-containing MR-TADF host material for green and red PhOLEDs.
- To investigate the effect of selenium incorporation on the photophysical properties and device performance.
- To reduce efficiency roll-off and enhance the operational stability of PhOLEDs.
Main Methods:
- Molecular design and synthesis of a selenium-containing MR-TADF host material (TDBA-SePh).
- Characterization of photophysical properties, including the reverse intersystem crossing (RISC) rate.
- Fabrication and testing of green and red PhOLED devices using the novel host material.
- Comparison of device performance with conventional host materials (e.g., mCP).
Main Results:
- The synthesized TDBA-SePh material demonstrated effective activation of the RISC process (3.91 × 10^4 s^-1) due to selenium incorporation.
- TDBA-SePh-based green and red PhOLEDs exhibited higher external quantum efficiency (EQE) compared to mCP-based devices.
- Significantly reduced efficiency roll-off was observed: 2.5% for green and 4.3% for red devices at 1000 cd m^-2.
- The improved performance is attributed to accelerated RISC and suppressed triplet-triplet annihilation (TTA).
Conclusions:
- Selenium incorporation into MR-TADF backbones is an effective strategy for enhancing PhOLED performance.
- The novel TDBA-SePh material significantly reduces efficiency roll-off and boosts device efficiency.
- This molecular design approach holds promise for developing next-generation OLEDs with improved stability and performance.
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