In-situ Raman analysis of hydrogenation in well-defined ultrathin molybdenum diselenide deposits synthesized through vapor phase deposition
| Autor: | Hadi Tavassol, Francisco Ramirez, Peter Joseph Santiago |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Solid-state chemistry
Materials science Hydrogen lcsh:Medicine chemistry.chemical_element 02 engineering and technology 010402 general chemistry 01 natural sciences Article chemistry.chemical_compound symbols.namesake Nano lcsh:Science Deposition (law) Multidisciplinary lcsh:R technology industry and agriculture 021001 nanoscience & nanotechnology Surface chemistry 0104 chemical sciences Blueshift chemistry Chemical engineering Molybdenum diselenide symbols lcsh:Q Materials chemistry 0210 nano-technology Raman spectroscopy Layer (electronics) Materials for energy and catalysis |
| Zdroj: | Scientific Reports Scientific Reports, Vol 10, Iss 1, Pp 1-8 (2020) |
| ISSN: | 2045-2322 |
| Popis: | We report on the synthesis, characterization and in-situ Raman spectroscopy analysis of hydrogenation in ultrathin crystalline MoSe2 deposits. We use a controllable vapor phase synthesis method using MoSe2 powder as the only precursor, to fabricate nano- to micro-size few layer thick MoSe2 deposits with tunable number densities on SiO2/Si substrates. We employ this controllable synthesis method to correlate characteristic Raman spectroscopy response of MoSe2 at ca. 242 cm−1 (A1g) and ca. 280 cm−1 (E2g1) with the thickness of the deposits acquired from atomic force microscopy (AFM). We also use this array of well-defined atomically thin MoSe2 deposits to study possible hydrogenation effects on select architectures using in-situ Raman spectroscopy. Interestingly, our analysis indicates that ultrathin MoSe2 deposits with exposed edges show a blue shift of 1–2 cm−1 when exposed to H2 flow at 150–250 sccm for 2–4 hours in a sealed reaction cell. Exposure to Ar flow under same condition reverses the observed shift in the A1g mode of the select MoSe2 deposits. Our measurements provide in-situ evidence for hydrogen adsorption on MoSe2 deposits at room temperature and insight into the possible active sites for hydrogen reactions on layered dichalcogenides at lower dimensions. |
| Databáze: | OpenAIRE |
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