Electrochemically activated polyaniline based ambipolar organic electrochemical transistor

Abstract

The organic electrochemical transistors (OECTs) are largely applied as bio‐ and ion‐sensor devices due to their performance in an aqueous environment with electrochemical doping/dedoping (reversible redox reactions) of the semiconducting layer through ion injection and also low (around 1 V) operation potentials. Aiming for the complementary circuits’ development and improvement of the sensors device, we report the application of spin coated polyaniline (PANI) in ambipolar OECT. The OECT operation is based on electrochemical protonation/deprotonation of PANI upon applied gate potential that was verified by cyclic voltammograms (CV) of PANI sample. The device operates in accumulation mode with on‐currents on the milliampere range due to the use of interdigitated array (IDA) microelectrodes architecture with a larger active area. Acid (HCl) doped PANI were applied in OECT device for comparison, and it presented improved performance with increasing drain‐source current up to 38%, reaching 4.8 mA for the n‐type device. This current increase is due to the narrower bandgap of doped PANI that affects the injection barrier. The HCl doped PANI was evaluated by UV‐Vis spectrophotometry and CV analysis. Using deionized water as electrolyte defunctionalized the PANI‐based OECT (no current modulation observed) because the absence of ions in the electrolyte interrupts the electrochemical doping. This is the opposite for the poly(3‐hexylthiophene) (P3HT)‐based electrolyte‐gated organic field‐effect transistor (EGOFET) due to the polymeric hydrophobicity nature that allows for field‐effect modulation in the electrolyte/semiconductor interface. The results presented may open new possibilities for bio‐ and ion‐sensors devices.

Polyaniline-Based Biological and Chemical Sensors: Sensing Mechanism, Configuration Design, and Perspective

“…(a) Schematic diagram of a typical PANI-based OECT structure. Reproduced with permission from ref . Copyright 2020 Wiley-VCH.…”

“…Consequently, the gain of the flexible PANI-on-chitosan OECT inverter circuit achieved 2.4. Compared to the complementary circuit constructed by n-type and p-type PEDOT:PSS, the PANI-based OECTs showed splendid matching characteristics in the complementary circuit systems with facile fabrication procedures. , Encouragingly, recent years have witnessed a surging interest in advanced OECT devices with low power consumption and biocompatibility, pertaining to their pragmatic potential in emerging fields such as biosignaling and neuromorphic devices.…”

Integrating Electrochemically Grown Nano‐Oxide and Polymer Films for Electrochromic Device: Achieving Near‐Infrared Shielding and Four‐Digit Efficiency

“…[ 24 ] Easy processability, high sturdiness, and extra stability make the polymer an excellent choice as an ECM. [ 25–27 ] Coupling an organic and an inorganic ECM layer, while fabricating a solid‐state ECD leads to a unique device design incorporating advantages of both the classes. It is reported that such hybrid devices are more efficient, highly stable and runs longer.…”

PEDOT:PSS versus Polyaniline: A Comparative Study of Conducting Polymers for Organic Electrochemical Transistors

“…In this study, OECTs based on two well-known conducting polymers, PEDOT:PSS and PANI, were fabricated, and their device performances and durability were optimized. By comparing the two types of conducting polymers, we aim to discuss more optimal conditions for OECTs using conducting polymers, especially the applicability of PANI-based OECTs, because there are few precedents [30,31].…”