Fig. 4: Performance comparison between pOECT and OECT.
From: Reconfiguration of organic electrochemical transistors for high-accuracy potentiometric sensing
a Transfer curves of an n-type OECT and pOECT operated at two different pH values with a pH-sensitive PANI electrode as the G or GS. The applied gate voltage is reported as VSG for the pOECT and –VGS for the OECT. Inset: IDS and IGS vs. VGS of the OECT (scaled). The sensing electrode (G or GS) is located in a separate chamber connected to the rest of the device via Ag/AgCl floating gates. b Electrochemical potentials of the n-type OECT (left) and pOECT (middle) components monitored during the transfer curve recorded at pH = 6. Right: the electrochemical potential of the GS measured during the acquisition of the transfer curves at different pH. c Relationship between the sensing interface (G and GS) polarization and the electrode diameter/area in a pOECT and OECT bearing the same n-type channel. G and GS are Au electrodes with varying diameters (Φ) and GG is an Au electrode of 1.6 mm-diameter. d 50 consecutive transfer curves with pOECT and OECT, where the G/GS is a 3 mm-diameter and GG is 1.6 mm-diameter Au electrode. e The 50th (final) transfer curve of the first cycling set (black) and the transfer curves recorded during the second set of cycling tests for the OECT. f Normalized response at VSG = −VGS = −0.55 V of the pOECT and OECT during one set of transfer curves and two consecutive sets of transfer curves respectively. g Transfer curves of an n-type pOECT recorded at different pH values (4, 7, and 10). The device has a pH-sensitive glass electrode as the GS and a Pt coil as the GG. GS is located in a separate chamber connected to the rest of the device via Ag/AgCl floating gates. The pOECT is an n-type enhancement-mode device. Inset: corresponding calibration curve.
