Chi‐Chun TsengKuang‐Chieh WangPo‐Shen LinChi ChangLi‐Lun YehShih‐Huang TungCheng‐Liang LiuYen‐Ju Cheng2024-07-022024-07-022024-05-1116136810https://www.scopus.com/record/display.uri?eid=2-s2.0-85192687127&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/719562While research on organic thermoelectric polymers is making significant progress in recent years, realization of a single polymer material possessing both thermoelectric properties and stretchability for the next generation of self-powered wearable electronics is a challenging task and remains an area yet to be explored. A new molecular engineering concept of “conjugated breaker” is employed to impart stretchability to a highly crystalline diketopyrrolepyrrole (DPP)-based polymer. A hexacyclic diindenothieno[2,3-b]thiophene (DITT) unit, with two 4-octyloxyphenyl groups substituted at the tetrahedral sp3-carbon bridges, is selected to function as the conjugated breaker that can sterically hinder intermolecular packing to reduce polymers’ crystallinity. A series of donor–acceptor random copolymers is thus developed via polymerizing the crystalline DPP units with the DITT conjugated breakers. By controlling the monomeric DPP/DITT ratios, DITT30 reaches the optimal balance of crystalline/amorphous regions, exhibiting an exceptional power factor (PF) value up to 12.5 µW m−1 K−2 after FeCl3-doping; while, simultaneously displaying the capability to withstand strains exceeding 100%. More significantly, the doped DITT30 film possesses excellent mechanical endurance, retaining 80% of its initial PF value after 200 cycles of stretching/releasing at a strain of 50%. This research marks a pioneering achievement in creating intrinsically stretchable polymers with exceptional thermoelectric properties.trueamorphous segmentdopingfused-ringorganic thermoelectricsstretchabilityjournal article10.1002/smll.2024019662-s2.0-85192687127