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Advanced Organic Transistor-Based Sensors Utilizing a Solvatochromic Medium with Twisted Intramolecular
Seungtaek Oh1,2, Md Rajibur Rahaman Khan3, Giheon Choi1,2
1Department of Materials Science and Chemical Engineering, Hanyang University, Ansan, Gyeonggi 15588, Republic of Korea.
ACS Applied Materials & Interfaces
|November 19, 2021
Summary
This study introduces an improved organic field-effect transistor (OFET) gas sensor using Nile red dye. The novel design enhances ammonia detection sensitivity and linearity, overcoming previous limitations.
Area of Science:
- Materials Science
- Chemical Sensing
- Organic Electronics
Background:
- Organic field-effect transistors (OFETs) show promise for gas sensing applications.
- Existing OFET sensors often suffer from saturation and limited linearity.
- Nile red (NR) dye exhibits solvatochromic and twisted intramolecular charge-transfer (TICT) properties sensitive to molecular polarity.
Purpose of the Study:
- To develop a highly sensitive and reliable OFET-based gas sensor for ammonia detection.
- To leverage the TICT behavior of Nile red as an auxiliary sensing medium (aNR-SM).
- To improve the response and recovery rates of OFET gas sensors.
Main Methods:
- Designed and fabricated an OFET-based gas sensor incorporating Nile red as an auxiliary sensing medium.
- Investigated the effect of molecular polarity on Nile red's TICT behavior.
- Optimized the placement of the aNR-SM, focusing on the 'Top-NR' configuration.
Main Results:
- The 'Top-NR' configuration demonstrated superior gas sensing performance compared to the pristine OFET.
- Response and recovery rates were significantly improved by 46% and 94%, respectively.
- Achieved high sensitivity (0.87 ± 0.045 ppm⁻¹%) with near-perfect linearity (0.999) for ammonia detection, resolving the saturation issue.
Conclusions:
- The developed OFET gas sensor utilizing Nile red's TICT behavior offers enhanced performance and reliability.
- This approach effectively addresses the saturation problem in OFET-based gas sensing.
- The study presents a viable strategy for improving the sensitivity and linearity of chemical sensors.
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