Thickness-Dependent Resonant Raman and E′ Photoluminescence Spectra of Indium Selenide and Indium Selenide/Graphene Heterostructures
| Autor: | Mariam Ali Almahri, Srinivasa Reddy Tamalampudi, Abdulrahman Al-Hagri, Boulos Alfakes, Adel B. Gougam, Ibraheem Almansouri, Matteo Chiesa, Harry Apostoleris, Jin-You Lu, Ru Li, Raman Sankar |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Photoluminescence Band gap Physics::Optics chemistry.chemical_element 02 engineering and technology 010402 general chemistry 01 natural sciences Spectral line law.invention Physics::Fluid Dynamics symbols.namesake chemistry.chemical_compound law Selenide Physical and Theoretical Chemistry VDP::Mathematics and natural science: 400 business.industry Graphene Heterojunction VDP::Matematikk og Naturvitenskap: 400 021001 nanoscience & nanotechnology 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials General Energy chemistry symbols Optoelectronics 0210 nano-technology business Raman spectroscopy Indium |
| Zdroj: | The Journal of Physical Chemistry C. 123:15345-15353 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/acs.jpcc.9b03457 |
| Popis: | This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review. To access the final edited and published work see https://doi.org/10.1021/acs.jpcc.9b03457 Atomically thin, two-dimensional (2D) indium selenide (InSe) has attracted considerable attention because of the dependence of its bandgap on sample thickness, making it suitable for small-scale optoelectronic device applications. In this work, by the use of Raman spectroscopy with three different laser wavelengths, including 488, 532, and 633 nm, representing resonant, near-resonant, and conventional nonresonant conditions, a conclusive understanding of the thickness dependence of lattice vibrations and electronic band structure of InSe and InSe/graphene heterostructures is presented. Combining our experimental measurements with first-principles quantum mechanical modeling of the InSe systems, we identified the crystal structure as ε-phase InSe and demonstrated that its measured intensity ratio of Raman peaks in the resonant Raman spectrum evolves with the number of layers. Moreover, graphene coating enhances Raman scattering of few-layered InSe and also makes its photoluminescence stable under higher intensity laser illumination. The optically induced charge transfer between van der Waals graphene/InSe heterostructures is observed under excitation of the E′ transition in InSe, where the observed mechanism may potentially be a route for future integrated electronic and optoelectronic devices. |
| Databáze: | OpenAIRE |
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