Liu Yufeng, Handa Taketo, Olsen Nicholas, Nuckolls Colin, Zhu Xiaoyang
Department of Chemistry, Columbia University, New York, New York 10027, United States.
J Am Chem Soc. 2024 Apr 10;146(14):10052-10059. doi: 10.1021/jacs.4c00956. Epub 2024 Mar 27.
Spin-polarized electrons can improve the efficiency and selectivity of photo- and electro-catalytic reactions, as demonstrated in the past with magnetic or magnetized catalysts. Here, we present a scheme in which spin-polarized charge separation occurs at the interfaces of nonmagnetic semiconductors and molecular films in the absence of a magnetic field. We take advantage of the spin-valley-locked band structure and valley-dependent optical selection rule in group VI transition metal dichalcogenide (TMDC) monolayers to generate spin-polarized electron-hole pairs. Photoinduced electron transfer from WS to fullerene (C) and hole transfer from MoSe to phthalocyanine (HPc) are found to result in spin polarization lifetimes that are 1 order of magnitude longer than those in the TMDC monolayers alone. Our findings connect valleytronic properties of TMDC monolayers to spin-polarized interfacial charge transfer and suggest a viable route toward spin-selective photocatalysis.
自旋极化电子可以提高光催化和电催化反应的效率和选择性，过去使用磁性或磁化催化剂已证明了这一点。在此，我们提出一种方案，即在无磁场的情况下，自旋极化电荷分离发生在非磁性半导体与分子薄膜的界面处。我们利用第VI族过渡金属二硫属化物（TMDC）单层中的自旋-谷锁定能带结构和谷依赖光学选择规则来产生自旋极化的电子-空穴对。发现从WS到富勒烯（C）的光致电子转移以及从MoSe到酞菁（HPc）的空穴转移导致的自旋极化寿命比仅在TMDC单层中的情况长1个数量级。我们的发现将TMDC单层的谷电子学性质与自旋极化界面电荷转移联系起来，并为自旋选择性光催化提出了一条可行的途径。
