Investigation of the Performance of Donor–Acceptor Conjugated Polymers in Electrolyte‐Gated Organic Field‐Effect Transistors

Abstract

Electrolyte‐gated organic field‐effect transistors (EGOFETs) are gaining interest for application in bioelectronic devices. However, robust performance in terms of charge‐carrier mobility, on‐to‐off drain current ratio (Ion/Ioff), and turn‐on speed are required for real application. Here, donor‐acceptor (D‐A) conjugated polymers, namely poly[2,5‐(2‐octyldodecyl)‐3,6‐diketopyrrolopyrrole‐alt‐5,5‐(2,5‐di(thien‐2‐yl)thieno[3,2‐b]thiophene)] (PDPPDTT) and indacenodithiophene‐co‐benzothiadiazole (PIDTBT), are evaluated in EGOFETs. The operational performance of these materials is compared to that of the well‐established conjugated polymer, poly[2,5‐bis(3‐hexadecylthiophen‐2‐yl)thieno[3,2‐b]thiophene] (PBTTT). The effective mobility extracted for the PDPPDTT (0.18 cm2 V−1 s−1), and PIDTBT (0.16 cm2 V−1 s−1) devices is almost double that of the PBTTT (0.10 cm2 V−1 s−1) based device and the Ion/Ioff is one ((PDPPDTT): 3 × 103) or two ((PIDTBT): 2 × 104) orders of magnitude higher than that of PBTTT (2 × 102) devices. The extracted values compare favorably to those of the highest performing EGOFETs and EGOFETs based on the D‐A polymers turn from off to on state two to ten times faster than the analogous PBTTT device with an improved subthreshold swing. These results show that D‐A polymers with a planar conjugated backbone enable the development of robust EGOFETs that are well appropriate for applications in bioelectronic devices.

Robust Microfluidic Integrated Electrolyte‐Gated Organic Field‐Effect Transistor Sensors for Rapid, In Situ and Label‐Free Monitoring of DNA Hybridization

“…[ 30,29 ] The improved operational stability may come from the more ordered morphology and the interdigitation of the alkyl side chains reducing water diffusion and ion doping. [ 18 ] Similarly, the initial I GS rapidly decreased to reach 96% of its minimum value after 100 s (lower panel of the inset of Figure 3a). The simultaneous variation of the I DS and I GS can be correlated with the time taken to establish the EDL at the interfaces, and it required about 100 s to reach the maximum capacitance.…”

“…This substrate was then spin‐coated with poly(diketopyrrolo‐pyrrole‐dithiophene‐thienothiophene) (PDPPDTT) (Figure 1a‐II.a). [ 18 ] PDPPDTT was selected as it has previously been established as a high performance material for use in EGOFETs. [ 18 ] Then a double‐sided tape (DST) with four laser cut flow channels was affixed on top of this PEN substrate to confine the electrolyte over the interdigitated electrodes (Figure 1a‐III.a).…”

“…[ 18 ] PDPPDTT was selected as it has previously been established as a high performance material for use in EGOFETs. [ 18 ] Then a double‐sided tape (DST) with four laser cut flow channels was affixed on top of this PEN substrate to confine the electrolyte over the interdigitated electrodes (Figure 1a‐III.a). On a second PEN substrate an array of sixteen 1 mm 2 gate electrodes was deposited by photolithography and this was affixed to a rigid PMMA sheet using DST (Figure 1a‐I.b).…”

“…It is worth noting that μ × C i and I on /I off of the developed device belong to the high end of what was reported in solution gated EGOFET to date: I on / I off from 10 to 10 4 and μ × C i from 0.003 to 0.5 μF V –1 s –1 . [ 18 ] Minor fluctuations from the mean values in V th (2% – 3%) were observed for devices on the same substrate (e.g., 0.43 ± 0.002 V) variation between substrates was larger (≈5%). Variation in the extracted μ × C i values was larger at ≈10% over one substrate and 17% between substrates.…”

Electrolyte-Gated Organic Field-Effect Transistors for Quantitative Monitoring of the Molecular Dynamics of Crystallization at the Solid–Liquid Interface

“…A Faraday cage was used to minimize electrical noise. 34 Representative transfer and output curves obtained using water and glycine solution are shown in Figure S5 . For the calibration, the current was measured for different glycine concentrations after the device operation was stabilized, i.e., at around 70 s after positioning of the droplet ( Figure S6 ).…”