Extended Data Fig. 1: Cyclic voltammetry (CV) and UV−vis−NIR spectro-electrochemical measurement.
From: Highly stretchable organic electrochemical transistors with strain-resistant performance
Cyclic voltammetry of (a) DPP-g2T and (b) DPP-2T drop-cast films on Pt electrodes. The oxidation onsets are +0.34 and +0.75 V for DPP-g2T and DPP-2T, respectively, indicating that DPP-g2T is more readily oxidized. The spectro-electrochemical properties of (c,e) DPP-g2T and control (d,f) DPP-2T films on ITO/glass were characterized under biases ranging from 0.0 V to +0.8 V (in 0.1 M aqueous KPF6) to investigate the electrochemical doping efficiency. For DPP-g2T, upon application of a low bias the intensities of the π–π* absorption (420 nm), intramolecular charge transfer (ICT, 783 nm), and π–π aggregate (848 nm) peaks decrease and polaronic absorption at longer wavelengths (> 1000 nm) increases, indicating full and efficient doping of DPP-g2T. In contrast, the DPP-2T films show no obvious absorption changes at biases ≤ +0.5 V and even at biases ≥ +0.8 V, while the absorption features of the neutral polymer persist, indicating poor electrochemical doping efficiency. In addition, the absorption spectrum of DPP-g2T returns to the original line shape when applying a bias of –0.2 V, while that of DPP-2T only partially recovers, indicating inferior redox stability, a result confirmed by CV measurements on the same platform.
