Enhancing Stability and Efficiency in Organic Thermoelectrics via a Dicationic Dopant: Structural Insights from TAB–2TFSI

Organic thermoelectric materials promise sustainable energy harvesting for applications like wearable electronics, but are hampered by poor doping efficiency and stability. We investigate a dicationic p-type dopant, TAB–2TFSI, which demonstrates high oxidative potential, ambient and thermal robustness, and excellent doping efficiency across diverse conjugated polymers. We hypothesize that this arises from a division of function between TAB²⁺ (electron acceptor) and TFSI⁻ (ionic compensator), enabling enhanced structural and thermal stability. To probe this mechanism, we propose a systematic GIWAXS study on four thermoelectric polymers doped with TAB–2TFSI under varying concentrations and annealing conditions. We will analyze π–π stacking distances, lamellar spacing, and crystalline coherence lengths to determine how doping alters polymer morphology. These insights will guide the rational design of next-generation dopants for high-performance, stable OTE devices.