Electronic Coupling in Metallophthalocyanine-Transition Metal Dichalcogenide Mixed-Dimensional Heterojunctions
| Autor: | Samuel H. Amsterdam, Nathaniel P. Stern, Mark C. Hersam, Tobin J. Marks, Pierre Darancet, Alexander J.T. Lou, Qunfei Zhou, Teodor K. Stanev, Hadallia Bergeron |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
General Engineering General Physics and Astronomy Heterojunction 02 engineering and technology Electronic structure 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics 0104 chemical sciences symbols.namesake Transition metal symbols General Materials Science Density functional theory 0210 nano-technology Electronic band structure Absorption (electromagnetic radiation) Raman spectroscopy Excitation |
| Zdroj: | ACS nano. 13(4) |
| ISSN: | 1936-086X |
| Popis: | Mixed-dimensional heterojunctions, such as zero-dimensional (0D) organic molecules deposited on two-dimensional (2D) transition metal dichalcogenides (TMDCs), often exhibit interfacial effects that enhance the properties of the individual constituent layers. Here we report a systematic study of interfacial charge transfer in metallophthalocyanine (MPc) - MoS2 heterojunctions using optical absorption and Raman spectroscopy to elucidate M core (M = first row transition metal), MoS2 layer number, and excitation wavelength effects. Observed phenomena include the emergence of heterojunction-specific optical absorption transitions and strong Raman enhancement that depends on the M identity. In addition, the Raman enhancement is tunable by excitation laser wavelength and MoS2 layer number, ultimately reaching a maximum enhancement factor of 30x relative to SiO2 substrates. These experimental results, combined with density functional theory (DFT) calculations, indicate strong coupling between nonfrontier MPc orbitals and the MoS2 band structure as well as charge transfer across the heterojunction interface that varies as a function of the MPc electronic structure. |
| Databáze: | OpenAIRE |
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