Tuning the Fermi Level of Graphene by Two-Dimensional Metals for Raman Detection of Molecules.

Autor:	Zhang N; Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States., Zhang K; Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States., Zou M; School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong 250353, People's Republic of China., Maniyara RA; Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States., Bowen TA; Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States., Schrecengost JR; Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States., Jain A; Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States., Zhou D; Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States., Dong C; Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States., Yu Z; Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States., Liu H; Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States., Giebink NC; Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.; Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109, United States., Robinson JA; Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.; Two-Dimensional Crystal Consortium, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.; Center for Two-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States., Hu W; School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong 250353, People's Republic of China., Huang S; Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States., Terrones M; Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.; Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.; Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.; Two-Dimensional Crystal Consortium, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.; Center for Two-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
Jazyk:	angličtina
Zdroj:	ACS nano [ACS Nano] 2024 Mar 26; Vol. 18 (12), pp. 8876-8884. Date of Electronic Publication: 2024 Mar 18.
DOI:	10.1021/acsnano.3c12152
Abstrakt:	Graphene-enhanced Raman scattering (GERS) offers great opportunities to achieve optical sensing with a high uniformity and superior molecular selectivity. The GERS mechanism relies on charge transfer between molecules and graphene, which is difficult to manipulate by varying the band alignment between graphene and the molecules. In this work, we synthesized a few atomic layers of metal termed two-dimensional (2D) metal to precisely and deterministically modify the graphene Fermi level. Using copper phthalocyanine (CuPc) as a representative molecule, we demonstrated that tuning the Fermi level can significantly improve the signal enhancement and molecular selectivity of GERS. Specifically, aligning the Fermi level of graphene closer to the highest occupied molecular orbital (HOMO) of CuPc results in a more pronounced Raman enhancement. Density functional theory (DFT) calculations of the charge density distribution reproduce the enhanced charge transfer between CuPc molecules and graphene with a modulated Fermi level. Extending our investigation to other molecules such as rhodamine 6G, rhodamine B, crystal violet, and F 16 CuPc, we showed that 2D metals enabled Fermi level tuning, thus improving GERS detection for molecules and contributing to an enhanced molecular selectivity. This underscores the potential of utilizing 2D metals for the precise control and optimization of GERS applications, which will benefit the development of highly sensitive, specific, and reliable sensors.
Databáze:	MEDLINE
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