Abstract: Organic thin-film transistors (OTFTs) are regarded as highly promising candidates for next-generation flexible electronics. However, device stability remains a major obstacle to OTFTs commercialization. Here, we propose the sandwich-structured composite dielectrics (OTS/DC 1-2577/SU8) for high-stability, high-performance, and high-uniformity organic devices. The composite dielectrics-based OTFTs demonstrate remarkable stability, with 15,000 s bias pressure stability and 25,700 switching cycles, outshining the well-established stable SiO₂ devices. Additionally, the device features a low defect state density and near-zero hysteresis. More strikingly, a 16 × 16 high-stability flexible OTFT array was successfully fabricated, achieving outstanding performance uniformity with a mobility coefficient of variation of only 3.8 %. This metric is superior to that of the previously reported large-area flexible OTFT arrays. This work ingeniously designs a sandwich-structured composite dielectrics integrating superior environmental, operational, and mechanical stability, offering a novel and widely applicable approach to developing high-stability, high-performance, and high-uniformity organic transistors and greatly accelerating their industrialization.

Key words: High-stability, Sandwich-structured composite dielectric layers, Organic transistors, High-uniformity, High-performance