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Terminal Hydroxylated Side-Chains Enhance Ionic-Electronic Coupling Efficiency in Small-Molecule Semiconductors
Jiaxing Pu1, Jinhao Zhou2, Haozhe Liu3
1Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, China.
Angewandte Chemie (International Ed. in English)
|May 21, 2026
Summary
Introducing hydroxylated ethylene glycol (EG-OH) side chains enhances small-molecule semiconductors for organic electronics. This strategy improves ionic-electronic coupling in organic mixed ionic-electronic conductors (OMIECs), boosting performance in organic electrochemical transistors (OECTs).
Area of Science:
- Materials Science
- Organic Electronics
- Semiconductor Physics
Background:
- Small-molecule semiconductors are vital for organic electronics but face limitations in ionic transport.
- Efficient ionic-electronic coupling is crucial for organic mixed ionic-electronic conductors (OMIECs).
- Current organic electrochemical transistors (OECTs) often exhibit suboptimal performance due to poor ionic conductivity.
Purpose of the Study:
- To develop a universal strategy for enhancing ionic transport in small-molecule semiconductors.
- To improve the performance of organic mixed ionic-electronic conductors (OMIECs) by introducing specific side chains.
- To investigate the impact of hydroxylated ethylene glycol (EG-OH) side chains on OECT performance.
Main Methods:
- Synthesized 4Cl-PDI-EG-OH small-molecule semiconductor with terminal EG-OH side chains.
- Investigated performance in organic electrochemical transistors (OECTs) comparing EG-OH with ethylene glycol (EG) based counterparts.
- Utilized X-ray single-crystal diffraction and spectroscopic studies to elucidate structural and electronic properties.
Main Results:
- The 4Cl-PDI-EG-OH demonstrated superior transconductance, faster response times, and enhanced stability compared to 4Cl-PDI-EG.
- Terminal hydroxyl interlocking in EG-OH chains promoted ordered arrangements, widening ionic transport channels.
- Induced short-range charge-transfer (CT)-coupled J-aggregates (JCT) maintained carrier mobility, enabling efficient ionic-electronic coupling.
- BTP-EG-OH achieved a transconductance of 101.9 mS, rivaling high-performance polymer-based OECTs.
Conclusions:
- The introduction of EG-OH side chains is a highly effective strategy for improving small-molecule OMIECs.
- EG-OH side chains offer significant advantages over conventional EG side chains for high-performance OECTs.
- This approach provides a pathway for developing next-generation organic electronic devices with enhanced efficiency and stability.
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