2024-03-29T11:06:45Zhttps://keep.lib.asu.edu/oai/requestoai:keep.lib.asu.edu:node-1284922021-12-10T22:19:59Zoai_pmh:all128492
https://hdl.handle.net/2286/R.I.44403
<p>Suslu, A., Wu, K., Sahin, H., Chen, B., Yang, S., Cai, H., . . . Tongay, S. (2016). Unusual dimensionality effects and surface charge density in 2D Mg(OH)2. Scientific Reports, 6(1). doi:10.1038/srep20525</p>
10.1038/srep20525
2045-2322
http://rightsstatements.org/vocab/InC/1.0/
http://creativecommons.org/licenses/by/4.0
2016-02-05
7 pages
eng
Tuna, Aslihan
Wu, Kedi
Sahin, Hasan
Chen, Bin
Yang, Sijie
Cai, Hui
Aoki, Toshihiro
Horzum, Seyda
Kang, Jun
Peeters, Francois M.
Tongay, Sefaattin
Ira A. Fulton Schools of Engineering
The final version of this article, as published in Scientific Reports, can be viewed online at: http://www.nature.com/articles/srep20525
<p>We present two-dimensional Mg(OH)<sub>2</sub> sheets and their vertical heterojunctions with CVD-MoS<sub>2</sub> for the first time as flexible 2D insulators with anomalous lattice vibration and chemical and physical properties. New hydrothermal crystal growth technique enabled isolation of environmentally stable monolayer Mg(OH)<sub>2</sub> sheets. Raman spectroscopy and vibrational calculations reveal that the lattice vibrations of Mg(OH)<sub>2</sub> have fundamentally different signature peaks and dimensionality effects compared to other 2D material systems known to date. Sub-wavelength electron energy-loss spectroscopy measurements and theoretical calculations show that Mg(OH)<sub>2</sub> is a 6 eV direct-gap insulator in 2D, and its optical band gap displays strong band renormalization effects from monolayer to bulk, marking the first experimental confirmation of confinement effects in 2D insulators. Interestingly, 2D-Mg(OH)<sub>2</sub> sheets possess rather strong surface polarization (charge) effects which is in contrast to electrically neutral h-BN materials. Using 2D-Mg(OH)<sub>2</sub> sheets together with CVD-MoS<sub>2</sub> in the vertical stacking shows that a strong change transfer occurs from n-doped CVD-MoS<sub>2</sub> sheets to Mg(OH)<sub>2</sub>, naturally depleting the semiconductor, pushing towards intrinsic doping limit and enhancing overall optical performance of 2D semiconductors. Results not only establish unusual confinement effects in 2D-Mg(OH)<sub>2</sub>, but also offer novel 2D-insulating material with unique physical, vibrational, and chemical properties for potential applications in flexible optoelectronics.</p>
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Unusual Dimensionality Effects and Surface Charge Density in 2D Mg(OH)2