日本国立材料研究所Yamashita, Yu团队报道了通过质子耦合电子转移的分子半导体掺杂。相关研究成果于2023年10月11日发表在《自然》。

分子半导体的化学掺杂是基于半导体和掺杂剂分子之间的电子转移反应；掺杂剂的氧化还原电势是控制半导体的费米能级的关键。化学掺杂的可调谐性和再现性受到掺杂剂材料的可用性和杂质（如水）的影响的限制。

该文中，研究人员报道了广泛用于生化过程的质子耦合电子转移（PCET）反应，该反应的氧化还原电位取决于一个容易处理的参数，即质子活性。研究人员将p型有机半导体薄膜浸入含有PCET基氧化还原对和疏水分子离子的水溶液中。PCET和离子嵌入的协同反应导致在环境条件下对结晶有机半导体薄膜进行有效的化学掺杂。根据能斯特方程，半导体的费米能级得到了可重复的高精度控制——室温下的热能约为2500meV，带边缘周围的热能超过几百meV。还提出了一种基于该方法的无参比电极电阻式pH传感器。半导体掺杂和质子活性（化学和生物化学过程中广泛使用的参数）之间的联系，可能有助于为环境半导体过程和生物分子电子学创建一个平台。

附：英文原文

Title: Doping of molecular semiconductors through proton-coupled electron transfer

Author: Ishii, Masaki, Yamashita, Yu, Watanabe, Shun, Ariga, Katsuhiko, Takeya, Jun

Issue&Volume: 2023-10-11

Abstract: The chemical doping of molecular semiconductors is based on electron-transfer reactions between the semiconductor and dopant molecules; here, the redox potential of the dopant is key to control the Fermi level of the semiconductor1,2. The tunability and reproducibility of chemical doping are limited by the availability of dopant materials and the effects of impurities such as water. Here we focused on proton-coupled electron-transfer (PCET) reactions, which are widely used in biochemical processes3,4; their redox potentials depend on an easily handled parameter, that is, proton activity. We immersed p-type organic semiconductor thin films in aqueous solutions with PCET-based redox pairs and hydrophobic molecular ions. Synergistic reactions of PCET and ion intercalation resulted in efficient chemical doping of crystalline organic semiconductor thin films under ambient conditions. In accordance with the Nernst equation, the Fermi levels of the semiconductors were controlled reproducibly with a high degree of precision—a thermal energy of about 25millielectronvolts at room temperature and over a few hundred millielectronvolts around the band edge. A reference-electrode-free, resistive pH sensor based on this method is also proposed. A connection between semiconductor doping and proton activity, a widely used parameter in chemical and biochemical processes, may help create a platform for ambient semiconductor processes and biomolecular electronics.

DOI: 10.1038/s41586-023-06504-8

Source: https://www.nature.com/articles/s41586-023-06504-8