Recently, the research team led by Professors Hu Wenping and Li Liqiang from the School of Science at Tianjin University made significant progress in studying the stability of n-type organic semiconductors. Their research findings were published in the prestigious journal Nature Materials under the title "Improving both performance and stability of n-type organic semiconductors by vitamin C." The corresponding authors are Professors Wenping Hu and Liqiang Li, and the first authors are Dr. Liqian Yuan, Dr. Yinan Huang, and Associate Researcher Xiaosong Chen.
Semiconductors are hailed as the "pearl" of national industry and the "grain" of integrated circuits. Organic semiconductors, with their advantages in design, synthesis, solution processing, and tunability, have opened a new path for organic integrated circuits that are inherently flexible, conformable, and suitable for large-area production. They are considered groundbreaking materials that could lead to future trillion-dollar industries such as flexible displays, human-computer interaction, and wearable electronics. However, the stability of n-type organic semiconductors has long been a critical challenge due to their sensitivity to environmental factors like water and oxygen. This sensitivity, especially to reactive oxygen species, severely impacts the electrical performance and stability of devices made from these semiconductors. Despite efforts to enhance the antioxidation capability of these materials through molecular design, the inherent high reactivity of organic radical anions produced during device operation has made overcoming this instability seem almost "innate" and a bottleneck in the field of organic electronics.
To address this issue, the team proposed a universal strategy using vitamin C to stabilize n-type organic semiconductors, significantly improving both the performance and stability of the materials and devices. Vitamin C acts through sacrificial oxidation and non-sacrificial triplet quenching during a cascade reaction to eliminate reactive oxygen species within the material and suppress their regeneration. This process provides long-lasting protection against oxidative damage and passivates potential electronic traps within the materials and devices. The n-type organic field-effect transistors (OFETs) protected by vitamin C showed remarkable improvements, with electron mobility increasing by up to 38 times, as well as enhanced operational stability and resistance to photo-oxidation, maintaining excellent performance in air for over 255 days. The antioxidation strategy also demonstrated exceptional uniformity and batch repeatability in large-area OFET arrays. Furthermore, complementary inverters produced using this strategy exhibited higher gain and greater environmental stability. This research offers a novel approach to addressing the stability challenges of n-type organic semiconductors. Vitamin C, as a key material, is environmentally friendly, low-cost, and easy to use, making this strategy highly scalable for industrial applications.
This research was supported by several funding programs, including the National Distinguished Youth Project (52225304), the National Natural Science Foundation of China (NSFC) Innovation Research Group Project (52121002), the National Key R&D Program (2018YFA0703200), the NSFC General Project (52073210), NSFC Youth Project (52073210), and the China Postdoctoral Science Foundation (2023M742591).
Paper Information: Liqian Yuan#, Yinan Huang#, Xiaosong Chen#, Yixuan Gao, Xiaonan Ma, Zhongwu Wang, Yongxu Hu, Jinbo He, Cheng Han, Jing Li, Zhiyun Li, Xuefei Weng, Rong Huang, Yi Cui, Liqiang Li*, and Wenping Hu* Improving both performance and stability of n-type organic semiconductors by vitamin C, Nat. Mater. 2024,https://doi.org/10.1038/s41563-024-01933-w.
