N-type organic electrochemical transistors with stability in water.

Alexander Giovannitti,Jonathan Rivnay,Aram Amassian,David A Hanifi,Sahika Inal,Christian B Nielsen,Muhammad R Niazi,George G Malliaras,Dan-Tiberiu Sbircea,Mary Donahue,Iain Mcculloch

doi:10.1038/ncomms13066

Abstract

Organic electrochemical transistors (OECTs) are receiving significant attention due to their ability to efficiently transduce biological signals. A major limitation of this technology is that only p-type materials have been reported, which precludes the development of complementary circuits, and limits sensor technologies. Here, we report the first ever n-type OECT, with relatively balanced ambipolar charge transport characteristics based on a polymer that supports both hole and electron transport along its backbone when doped through an aqueous electrolyte and in the presence of oxygen. This new semiconducting polymer is designed specifically to facilitate ion transport and promote electrochemical doping. Stability measurements in water show no degradation when tested for 2 h under continuous cycling. This demonstration opens the possibility to develop complementary circuits based on OECTs and to improve the sophistication of bioelectronic devices.

Highlights

Organic electrochemical transistors (OECTs) are receiving significant attention due to their ability to efficiently transduce biological signals
The advantage of OECT-based sensors compared to organic field-effect transistor (OFET)-based sensors is that ions in the former interact with the whole volume of the active material, giving rise to lower impedance and higher transconductance[6]
We focus on the highly electron-deficient 2,6-dibromonaphthalene-1,4,5,8tetracarboxylic diimide (NDI) monomer which can be copolymerized with electron-rich thiophene based co-monomers

Summary

Introduction

Organic electrochemical transistors (OECTs) are receiving significant attention due to their ability to efficiently transduce biological signals. We report the first ever n-type OECT, with relatively balanced ambipolar charge transport characteristics based on a polymer that supports both hole and electron transport along its backbone when doped through an aqueous electrolyte and in the presence of oxygen. Stability measurements in water show no degradation when tested for 2 h under continuous cycling This demonstration opens the possibility to develop complementary circuits based on OECTs and to improve the sophistication of bioelectronic devices. The development of appropriate semiconductor materials is a major challenge: It requires that a material be both stable in an aqueous electrolyte, and that it be reversibly reduced and oxidized within the electrochemical window imparted by that electrolyte This requires the design of materials that concurrently have a high electron affinity (EA), a low ionization potential and the capacity for facile ion penetration. This work paves the way for the fabrication of OECT complementary circuits

Methods

Results

Conclusion