Karışık iyon–elektronik polimer iletkenlerin ultra hızlı spektroelektrokimyası

Electron transfer and switching mechanisms in conducting polymers remain an open question. When conventional electrochemical techniques such as cyclic voltammetry are employed alone, the measured current inevitably contains contributions from both the redox process of the polymer and the capacitive charging current arising from the voltage-dependent capacitance. Thus, isolating the pure redox current requires additional deconvolution methods. Furthermore, the conventional understanding, repeatedly emphasized in the literature, is that electron transfer in conducting polymers proceeds through an ion-coupled mechanism, in which counter-ions from the electrolyte penetrate into the polymer to maintain charge neutrality. In this thesis, we challenge this conventional description by employing operando ultrafast cyclic voltammetry–UV–Vis spectroscopy, in which the potential is rapidly scanned within a defined range while the spectroscopic response is simultaneously recorded. By extending the sweep rate up to 200,000 V/s, we aimed to suppress net counter-ion displacement. Under these conditions, the observed color change demonstrated that electron transfer can occur even in the absence of ion participation. To this end, operando ultrafast cyclic voltammetry–UV–Vis spectroscopy was utilized. The average spectroscopic responses obtained at ultrafast cycles were deconvoluted into their minimal components using principal component analysis (PCA), and the dependence of the resulting coefficients on the sweep rate was systematically examined. Analysis of these coefficients revealed that, with increasing sweep rate, the relative lifetime of the more oxidized and reduced states changes: counter-ion diffusion becomes increasingly limited, making doping less efficient and leading to a greater contribution from the reduced state. Moreover, optical charge values derived from the PCA coefficients approached steady-state at high sweep rates. These findings provide direct spectroscopic evidence that electron transfer in conducting polymers can proceed independently of ion motion under ultrafast potential modulation.