Spectroscopic Tools to Investigate the Electrochemical Doping Kinetics and Efficiency in Organic Semiconductors

Understanding the electrochemical doping of organic semiconductors plays a crucial role in the cur- rent development of organic electronics. In this short review, we present how temperature- and time-depen- dent visible-near-infrared (Vis-NIR) spectroelectrochemistry and terahertz spectroscopy, combined with mul- tivariate curve resolution analysis, can inform on the fundamental mechanisms governing the doping kinetics and efficiency of two archetypal semiconducting polymers (PEDOT and P3HT). We highlight the experimental procedures and data analysis performed to access (i) the thermodynamic parameters driving the extent and dynamics of electrochemical reactions in doped systems and (ii) how the density and nature of charged spe- cies (polarons, bipolarons) impact the charge carrier delocalization, effective THz mobility and hence short- range conductivity.