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

Abstract

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 ( I on / I off ), 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 cm 2 V −1 s −1 ), and PIDTBT (0.16 cm 2 V −1 s −1 ) devices is almost double that of the PBTTT (0.10 cm 2 V −1 s −1 ) based device and the I on / I off is one ((PDPPDTT): 3 × 10 3 ) or two ((PIDTBT): 2 × 10 4 ) orders of magnitude higher than that of PBTTT (2 × 10 2 ) 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.