Narrowband Emissive Solution-Processed Polymer Organic Light-Emitting Diodes with External Quantum Efficiency Above
1School of Materials Science & Engineering, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou, 213164, China.
Advanced Materials (Deerfield Beach, Fla.)
|March 28, 2025
Summary
Researchers developed new thermally activated delayed fluorescence (TADF) polymers for efficient, narrowband emission. A silicon-carbon spacer improved performance, achieving high quantum yields and external quantum efficiencies in devices.
Area of Science:
- Materials Science
- Organic Electronics
- Photophysics
Background:
- Achieving high efficiency and narrowband emission simultaneously in TADF polymers is a significant challenge.
- Existing TADF polymer designs often struggle to balance these critical performance metrics.
Purpose of the Study:
- To propose and demonstrate a novel strategy for creating highly efficient and narrowband-emissive TADF polymers.
- To investigate the effect of a σ-bond saturated spacer on the optoelectronic properties of TADF polymers.
Main Methods:
- Synthesized a series of TADF polymers (PSix) by incorporating a silicon-carbon σ-bond saturated spacer between a multiresonance (MR) TADF unit and a polycarbazole backbone.
- Characterized the photophysical properties (emission spectra, quantum yield) and device performance (external quantum efficiency) of the synthesized polymers.
- Utilized a TADF molecule (5Cz-TRZ) as a sensitizer to further enhance device performance.
Main Results:
- All synthesized PSix polymers exhibited narrowband emission with FWHM of 28-30 nm in solution.
- Polymer PSi3 achieved a high photoluminescence quantum yield of 97% in doped films.
- Solution-processed devices based on PSi3 demonstrated a maximum EQE of 28.8% and an FWHM of 42 nm.
- Device performance was further enhanced to an EQEmax of 30.2% using 5Cz-TRZ as a sensitizer, positioning it among the top-performing MR-TADF polymers.
Conclusions:
- Embedding a σ-bond saturated spacer is an effective strategy for developing highly efficient and narrowband-emissive TADF polymers.
- The developed TADF polymers show great promise for applications in organic electronics, particularly in displays and lighting.
