用于表面增强拉曼散射分析的金属有机化合物薄膜的起源：电磁增强还是化学增强？

The Origin of MoC Films for Surface-Enhanced Raman Scattering Analysis: Electromagnetic or Chemical Enhancement?

作者信息

Ji Chang, Lu Jinxuan, Shan Baojie, Li Fengrui, Zhao Xiaofei, Yu Jing, Xu Shicai, Man Baoyuan, Zhang Chao, Li Zhen

机构信息

Shandong Provincial Engineering and Technical Center of Light Manipulation, School of Physics and Electronics, Shandong Normal University, Jinan 250014, P.R. China.

Shandong Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, P.R. China.

出版信息

J Phys Chem Lett. 2022 Sep 29;13(38):8864-8871. doi: 10.1021/acs.jpclett.2c02392. Epub 2022 Sep 20.

DOI:10.1021/acs.jpclett.2c02392

PMID:36125003

Abstract

The relatively weak Raman enhanced factors of semiconductor-based substrate limit its further application in surface-enhanced Raman scattering (SERS). Here, a kind of two-dimensional (2D) semimetal material, molybdenum carbide (MoC) film, is prepared via a chemical vapor deposition (CVD) method, and the origin of SERS is investigated for the first time. The detection limits of the prepared MoC films for crystal violet (CV) and rhodamine 6G (R6G) molecules are low at 10 M and 10 M, respectively. Our detailed theoretical analysis, based on density functional theory and the finite element method, demonstrates that the enhancement of the 2D MoC film is indeed CM in nature rather than the EM effects. Besides, the basic doping strategies are proposed to further optimize the SERS sensitivity of MoC for Fermi level regulation. We believe this work will provide a helpful guide for developing a highly sensitive semimetal SERS substrate.

摘要

基于半导体的基底相对较弱的拉曼增强因子限制了其在表面增强拉曼散射（SERS）中的进一步应用。在此，通过化学气相沉积（CVD）方法制备了一种二维（2D）半金属材料碳化钼（MoC）薄膜，并首次研究了其SERS的起源。所制备的MoC薄膜对结晶紫（CV）和罗丹明6G（R6G）分子的检测限分别低至10⁻¹¹ M和10⁻¹² M。我们基于密度泛函理论和有限元方法的详细理论分析表明，二维MoC薄膜的增强本质上确实是电荷转移（CM）而非电磁（EM）效应。此外，还提出了基本的掺杂策略以进一步优化MoC对费米能级调控的SERS灵敏度。我们相信这项工作将为开发高灵敏度半金属SERS基底提供有益的指导。