Kurosawa Tadanori, Okamoto Toshihiro, Yamashita Yu, Kumagai Shohei, Watanabe Shun, Takeya Jun
Material Innovation Research Center (MIRC) and Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan.
AIST-UTokyo Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan.
Adv Sci (Weinh). 2021 Dec;8(24):e2101998. doi: 10.1002/advs.202101998. Epub 2021 Oct 28.
Increasing the doping level of semiconducting polymer using strong dopants is essential for achieving good electrical conductivity. As for p-dopant, raising the electron affinity of a neutral compound through the dense introduction of electron-withdrawing group has always been the predominant strategy to achieve strong dopant. However, this simple and intuitive strategy faces extendibility, accessibility, and stability issues for further development. Herein, the use of dicationic state of tetraaryl benzidine (TAB ) in conjunction with bis(trifluoromethylsulfonyl)imide anion (TFSI ) as a strong and atmospherically stable p-dopant (TAB-2TFSI), for which the concept is hinted from a rapid and spontaneous dimerization of radical cation dopant, is demonstrated. TAB-2TFSI possesses a large redox potential such that it would have deteriorated when in contact with H O. However, no trace of degradation after 1 year of storage under atmospheric conditions is observed. When doping the state-of-the-art semiconducting polymer with TAB-2TFSI, a high doping level together with significantly enhanced crystallinity is achieved which led to an electrical conductivity as high as 656 S cm . The concept of utilizing charged molecule as a dopant is highly versatile and will potentially accelerate the development of a strong yet stable dopant.
使用强掺杂剂提高半导体聚合物的掺杂水平对于实现良好的导电性至关重要。对于p型掺杂剂，通过密集引入吸电子基团来提高中性化合物的电子亲和力一直是实现强掺杂剂的主要策略。然而，这种简单直观的策略在进一步发展中面临着扩展性、可及性和稳定性问题。在此，证明了使用四芳基联苯胺（TAB）的双阳离子状态与双（三氟甲基磺酰）亚胺阴离子（TFSI）结合作为一种强大且大气稳定的p型掺杂剂（TAB-2TFSI），其概念源自自由基阳离子掺杂剂的快速自发二聚化。TAB-2TFSI具有较大的氧化还原电位，以至于它在与水接触时会变质。然而，在大气条件下储存1年后未观察到降解痕迹。当用TAB-2TFSI掺杂最先进的半导体聚合物时，实现了高掺杂水平以及显著增强的结晶度，这导致电导率高达656 S/cm。利用带电分子作为掺杂剂的概念具有高度的通用性，并有望加速强大且稳定的掺杂剂的开发。
