Thin-layer indium selenide (InSe) compounds, as two-dimensional (2D) semiconductors, have been widely and intensively studied due to their high electron mobility and environmental stability. Here, we report a study demonstrating the oxygen-induced degradation of monolayer and bilayer InSe nanosheets using first-principles calculations and deformation potential theory. It is evident that O atoms prefer to substitute Se atoms instead of undergoing adsorption onto surfaces, while interstitial sites are the most stable adsorption sites of O atoms in the interior for both monolayer and bilayer InSe. Using the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional, we calculated band structures and carrier mobility. The band gaps of a monolayer or bilayer InSe nanosheet with O atoms remained unchanged and corresponded to the pristine structure except for a slight decrease in the substituted cases. Additionally, no impurity levels are observed, indicating that the addition of O atoms has little effect on carrier concentrations. With the calculated mobility of monolayer InSe with and without O atoms, we show that the degradation is governed by the interstitial impurity of O atoms, whose electron mobility can decrease by 3-4 orders of magnitude. As for bilayer InSe, there is a one order of magnitude decrease at most, which indicates a stronger resistance to oxidation than that of the monolayer structure. Our calculations provide a detailed understanding of the degradation induced by O atoms from the aspects of structures and electronic properties, which is a foundation for the application and modification of thin-layer InSe.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/c7cp07446h | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Atomic-level polarization reversal in sliding ferroelectric semiconductors.
Nat Commun
May 2024
Key Laboratory of Polar Materials and Devices (MOE), School of Physics and Electronic Science, East China Normal University, Shanghai, 200062, China.
Article Synopsis
- Researchers have observed atomic-level interlayer sliding dynamics and polarization reversal in yttrium-doped γ-InSe, a van der Waals layered material.
- The study reveals real-time sliding occurring in a 1/3-unit cell along the armchair direction, facilitated by low-energy electron-beam illumination, indicating low switching barriers.
- The findings introduce a new sliding mechanism and contribute significantly to the understanding of sliding ferroelectrics for applications in non-volatile storage and ferroelectric field-effect transistors.
Intertwisted bilayers of two-dimensional (2D) materials can host low-energy flat bands, which offer opportunity to investigate many intriguing physics associated with strong electron correlations. In the existing systems, ultra-flat bands only emerge at very small twist angles less than a few degrees, which poses a challenge for experimental studies and practical applications. Here, we propose a new design principle to achieve low-energy ultra-flat bands with increased twist angles.
View Article and Find Full Text PDFWeak ferroelectric charge transfer in layer-asymmetric bilayers of 2D semiconductors.
Sci Rep
June 2021
Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.
In bilayers of two-dimensional semiconductors with stacking arrangements which lack inversion symmetry charge transfer between the layers due to layer-asymmetric interband hybridisation can generate a potential difference between the layers. We analyse bilayers of transition metal dichalcogenides (TMDs)-in particular, [Formula: see text]-for which we find a substantial stacking-dependent charge transfer, and InSe, for which the charge transfer is found to be negligibly small. The information obtained about TMDs is then used to map potentials generated by the interlayer charge transfer across the moiré superlattice in twistronic bilayers.
View Article and Find Full Text PDFElectronic Structures of Twisted Bilayer InSe/InSe and Heterobilayer Graphene/InSe.
ACS Omega
May 2021
College of Physics Science and Technology, Yangzhou University, Yangzhou 225002, China.
Building vertical van der Waals heterojunctions between two-dimensional layered materials has become a promising strategy for modulating the properties of two-dimensional materials. Herein, we investigate the electronic structures of non-twisted/twisted bilayer InSe/InSe and heterobilayer graphene/InSe (Gr/InSe) by employing density functional theory calculations. For twisted bilayer InSe/InSes, their interlayer distances and band gaps are almost identical but a bit larger than those of the AB-stacking one due to the spontaneous polarization.
View Article and Find Full Text PDFDirect band gap and strong Rashba effect in van der Waals heterostructures of InSe and Sb single layers.
J Phys Condens Matter
February 2021
Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
Van der Waals heterostructures formed by stacking different types of 2D materials are attracting increasing attention due to new emergent physical properties such as interlayer excitons. Recently synthesized atomically thin indium selenide (InSe) and antimony (Sb) individually exhibit interesting electronic properties such as high electron mobility in the former and high hole mobility in the latter. In this work, we present a first-principles investigation on the stability and electronic properties of ultrathin bilayer heterostructures composed of InSe and Sb single layers.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!