Suchergebnisse

WOS: 000406926600001 ; Optical and electronic properties of black phosphorus strongly depend on the number of layers and type of stacking. Using first-principles calculations within the framework of density functional theory, we investigate the electronic properties of bilayer black phosphorus with an interlayer twist angle of 90 degrees. These calculations are complemented with a simple (k) over right arrow . (p) over right arrow model which is able to capture most of the low energy features and is valid for arbitrary twist angles. The electronic spectrum of 90 degrees twisted bilayer black phosphorus is found to be x-y isotropic in contrast to the monolayer. However x-y anisotropy, and a partial return to monolayer-like behavior, particularly in the valence band, can be induced by an external out-of-plane electric field. Moreover, the preferred hole effective mass can be rotated by 90 degrees simply by changing the direction of the applied electric field. In particular, a +0.4 (-0.4) V angstrom(1) out-of-plane electric field results in a similar to 60% increase in the hole effective mass along the y (x) axis and enhances the m(y)*/m(x)* (m(x)*/m(y)*) ratio as much as by a factor of 40. Our DFT and (k) over right arrow . (p) over right arrow simulations clearly indicate that the twist angle in combination with an appropriate gate voltage is a novel way to tune the electronic and optical properties of bilayer phosphorus and it gives us a new degree of freedom to engineer the properties of black phosphorus based devices. ; Scientific and Technological Research Council of Turkey (TUBITAK); FWO-Flanders; Flemish Science Foundation (FWO-Vl); Methusalem foundation of the Flemish government; Hercules foundation; TUBITAK [115F024]; ERC Synergy grant Hetero2D; EU Graphene Flagship Project ; This work was supported by the bilateral project between the The Scientific and Technological Research Council of Turkey (TUBITAK) and FWO-Flanders, Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRGrid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. We acknowledge the support from TUBITAK (Grant No. 115F024), ERC Synergy grant Hetero2D and the EU Graphene Flagship Project. We also thank Vladimir Fal'ko for helpful discussions.

The chemical bulk reductive covalent functionalization of thin-layer black phosphorus (BP) using BP intercalation compounds has been developed. Through effective reductive activation, covalent functionalization of the charged BP by reaction with organic alkyl halides is achieved. Functionalization was extensively demonstrated by means of several spectroscopic techniques and DFT calculations; the products showed higher functionalization degrees than those obtained by neutral routes. ; A.H. and G.A. acknowledge the European Research Council (ERC Advanced Grant 742145 B‐PhosphoChem to A.H., and ERC Starting Grant 2D‐PnictoChem 804110 to G.A.) for support. The research leading to these results was partially funded by the European Union Seventh Framework Programme under grant agreement No. 604391 Graphene Flagship. G.A. has received financial support through the Postdoctoral Junior Leader Fellowship Programme from "la Caixa" Banking Foundation (LCF/BQ/PI18/11630018). G.A. thanks the Deutsche Forschungsgemeinschaft (DFG; FLAG‐ERA AB694/2‐1), the Generalitat Valenciana (SEJI/2018/034 grant), and the FAU (Emerging Talents Initiative grant #WS16‐17_Nat_04) for support. A.H. and A.G. thank the SFB 953 "Synthetic Carbon Allotropes" funded by the DFG for support and the Cluster of Excellence "Engineering of Advanced Materials". A.G. is grateful for funding from the Free State of Bavaria (Research Network "Solar Technologies go Hybrid"). A.M. thanks the Alexander von Humboldt (AvH) Foundation for a postdoctoral fellowship. This work was supported by the MINECO (Spain) through the Excellence Unit María de Maeztu (MDM‐2015‐0538) and the Project CTQ2017‐86735‐P.

This is the peer reviewed version of the following article: Ares, P., Palacios, J. J., Abellán, G., Gómez‐Herrero, J., & Zamora, F. Recent progress on antimonene: a new bidimensional materiaAdvanced Materials 30.2 (2018): 1703771, which has been published in final form at https://doi.org/10.1002/adma.201703771. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions ; Antimonene, defined in sensu stricto as a single layer of antimony atoms, is recently the focus of numerous theoretical works predicting a variety of interesting properties and is quickly attracting the attention of the scientific community. However, what places antimonene in a different category from other 2D crystals is its strong spin–orbit coupling and a drastic evolution of its properties from the monolayer to the few-layer system. The recent isolation of this novel 2D material pushes the interest for antimonene even further. Here, a review of both theoretical predictions and experimental results is compiled. First, an account of the calculations anticipating an electronic band structure suitable for optoelectronics and thermoelectric applications in monolayer form and a topological semimetal in few-layer form is given. Second, the different approaches to produce antimonene—mechanical and liquid phase exfoliation, and epitaxial growth methods—are reviewed. In addition, this work also reports the main characterization techniques used to study this exotic material. This review provides insights for further exploring the appealing properties of antimonene and puts forward the opportunities and challenges for future applications from (opto)electronic device fabrication to biomedic ; The authors thank financial support from the Spanish Ministerio de Economía y Competitividad through the "María de Maeztu" Programme for Units of Excellence in R&D (MDM‐2014‐0377) and the projects MAT2016‐77608‐C3‐1‐P and ‐C3‐3‐P, and FIS2016‐80434‐P. The authors also acknowledge the European Union structural funds and the Comunidad de Madrid under grant MAD2D No. S2013/MIT‐3007, the Generalitat Valenciana under grant No. PROMETEO/2012/011, and the Fundación Ramón Areces. The research leading to these results was partially funded by the European Union Seventh Framework Programme under grant agreement No. 604391 Graphene Flagship. The authors thank the Deutsche Forschungsgemeinschaft (DFG‐SFB 953 "Synthetic Carbon Allotropes," Project A1) for financial support. G.A. thanks the FAU for the Emerging Talents Initiative (ETI) grant #WS16‐17_Nat_04