Lin, Chia-YangChia-YangLinWu, Guan-LinGuan-LinWuWang, Ting-YuTing-YuWangHe, WanerWanerHeWu, Ying-ShengYing-ShengWuImaoka, ShunsukeShunsukeImaokaShimizu, ShoheiShoheiShimizuChen, Wen-ChangWen-ChangChenSagara, YoshimitsuYoshimitsuSagaraCHU-CHEN CHUEHMichinobu, TsuyoshiTsuyoshiMichinobu2025-07-302025-07-302025-06-06https://www.scopus.com/record/display.uri?eid=2-s2.0-105008585015&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/730805Recent studies have shown that introducing vinylene bridges into naphthalenediimide (NDI)-based dual-acceptor copolymers is an effective strategy to improve backbone coplanarity and charge transport properties in organic field-effect transistors (OFETs). However, their potential as multifunctional materials for broader optoelectronic applications remains unexplored. In this study, we designed and synthesized four vinylene-bridged NDI (vNDI)-based conjugated polymers containing benzothiadiazole (S), benzotriazole (N), triazolobenzothiadiazole (NS), and benzobistriazole (NN) as second acceptors. Structural analysis revealed that the backbone conformation and electron-withdrawing ability of the acceptors significantly influence optical and electronic properties. Among them, vNDI-NS exhibited the narrowest optical bandgap (1.05 eV), while vNDI-N displayed the highest ambipolar mobility in OFETs, attributed to enhanced crystallinity and improved π-π stacking. Furthermore, these polymers were applied as photothermal membranes in solar steam generation (SSG) devices. Films based on vNDI-NS and vNDI-NN achieved solar-to-vapor conversion efficiencies of 58.3% and 56.4%, respectively, under 1 sun illumination. This study expands the applications of vNDI-based polymers beyond OFETs, providing a dual-functional platform combining electrical and photothermal performance.false[SDGs]SDG7journal article10.1039/d5lp00136f2-s2.0-105008585015