Red-to-Ultraviolet Emission Tuning of Two-Dimensional Gallium Sulfide/Selenide
| Autor: | Hong Seok Kang, Dong Myung Jang, Fazel Shojaei, Hyungsoon Im, Kidong Park, Jin Young Oh, Jeunghee Park, Chan Su Jung |
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| Rok vydání: | 2015 |
| Předmět: |
Potential well
Nanostructure Materials science Band gap business.industry Alloy General Engineering General Physics and Astronomy Nanotechnology engineering.material Epitaxy medicine.disease_cause chemistry.chemical_compound chemistry Selenide Monolayer engineering medicine Optoelectronics General Materials Science business Ultraviolet |
| Zdroj: | ACS Nano. 9:9585-9593 |
| ISSN: | 1936-086X 1936-0851 |
| DOI: | 10.1021/acsnano.5b04876 |
| Popis: | Graphene-like two-dimensional (2D) nanostructures have attracted significant attention because of their unique quantum confinement effect at the 2D limit. Multilayer nanosheets of GaS-GaSe alloy are found to have a band gap (Eg) of 2.0-2.5 eV that linearly tunes the emission in red-to-green. However, the epitaxial growth of monolayers produces a drastic increase in this Eg to 3.3-3.4 eV, which blue-shifts the emission to the UV region. First-principles calculations predict that the Eg of these GaS and GaSe monolayers should be 3.325 and 3.001 eV, respectively. As the number of layers is increased to three, both the direct/indirect Eg decrease significantly; the indirect Eg approaches that of the multilayers. Oxygen adsorption can cause the direct/indirect Eg of GaS to converge, resulting in monolayers with a strong emission. This wide Eg tuning over the visible-to-UV range could provide an insight for the realization of full-colored flexible and transparent light emitters and displays. |
| Databáze: | OpenAIRE |
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