Synthesis engineering and development of emergent conducting pi-conjugated materials: applications in energy harvesting and storage devices

Abstract

The synthesis engineering and development of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) have revolutionized the field of conducting π-conjugated materials, offering a robust and versatile platform for energy harvesting and storage applications. By fine-tuning synthesis parameters and doping strategies, the optoelectronic properties of PEDOT:PSS can be tailored for specific optoelectronic applications. Here, we report on recent advancements in the synthesis engineering of PEDOT:PSS inks, specially developed for energy harvesting and storage devices. Of particular interest is the application of the synthesized PEDOT:PSS inks as p-type organic thermoelectric materials, hole-transport layers (HTLs) in organic solar cells (OSCs), and battery/supercapacitor electrodes. The PEDOT:PSS inks synthesized herein, based on the Louwet route, were compared with state-of-the-art commercially available PEDOT:PSS inks, demonstrating similar or superior performances. For thermoelectric generators (TEGs), our best formulation exhibited a Seebeck coefficient of approximately 12.6 μV K⁻¹, surpassing the 12.3 μV K⁻¹ of the commercial PEDOT:PSS ink (Clevios™ PH 1000). In OSCs, our HTL proprietary ink achieved efficiencies and photovoltaic parameters comparable to those of the well-known commercial Clevios™ P VP AI 4083. Similar results were obtained in energy storage devices, where the conductive PEDOT:PSS synthesized herein outperformed commercially available formulations, both in open-circuit voltage and in discharge tests. The insights presented in this manuscript underscore the critical role of fine-tuning and synthesis engineering in advancing high-performance and scalable energy harvesting and storage devices.