Facile Solvent Treatment of PEDOT:PSS toward High Electromagnetic Interference Shielding Effectiveness

Electromagnetic interference (EMI) shielding materials combining high flexibility, exceptional electrical conductivity, lightweight properties, and superior shielding performance remain crucial for modern microelectronic applications. This study presents a secondary doping approach employing dodecylbenzenesulfonic acid (DBSA) and concentrated sulfuric acid (H2SO4) to engineer highly conductive poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) films. While DBSA treatment induced gelation of the PEDOT:PSS matrix and achieved a 6-fold lower conductivity compared to H2SO4-treated samples (reaching 63.6 dB), it yielded exceptional EMI shielding performance with a remarkable specific shielding effectiveness of 12,960 dB cm2 g–1. This outstanding performance was attributed to the synergistic interplay between the development of a layered architecture within the film and the significant enhancement in film thickness. Furthermore, the PEDOT:PSS/DBSA films demonstrated exceptional environmental stability, maintaining shielding effectiveness above 60 dB under harsh conditions, a performance benchmark meeting stringent military-grade requirements. This study underscores the critical balance between conductivity and microstructure attributes in governing shielding performance and presents a promising avenue for the development of highly efficient, flexible EMI shielding materials.