First principles calculations of relationship between the Cu surface states and relaxations

2007 ◽  
Vol 16 (5) ◽  
pp. 1429-1433 ◽  
Author(s):  
Xie Yao-Ping ◽  
Luo Ying ◽  
Liu Shao-Jun
Keyword(s):  
First Principles ◽  
Surface States ◽  
First Principles Calculations

Magnetism and Half-Metallicity in (100) Surface of Inverse Heusler Mn2CoSb

2014 ◽  
Vol 1015 ◽  
pp. 377-380
Author(s):  
Tao Chen ◽  
Ying Chen ◽  
Yin Zhou ◽  
Hong Chen
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
First Principles ◽  
Heusler Alloy ◽  
Density Functional ◽  
Magnetic Moments ◽  
Surface States ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Functional Theory

Using the first-principles calculations within density functional theory (DFT), we investigated the electronic and magnetic properties of (100) surface of inverse Heusler alloy Mn2CoSb with five different terminations. Our work reveals that the surface Mn atom moves to vacuum while surface Co atom moves to slab. Moreover, duo to the reason that the surface atom lost half of the nearest atoms with respect to the bulk phase, resulting in the decrease of hybridization, the atom-resolved spin magnetic moments of surface atoms are enhanced. Further investigation on DOS and PDOS showed that half-metallicity was preserved only in SbSb-termination while was destroyed in MnCo-, MnSb-, MnMn-, and CoCo-termination due to the appearance of surface states.

First-Principles Calculations of AlN Nanowires and Nanotubes:  Atomic Structures, Energetics, and Surface States

2006 ◽  
Vol 110 (17) ◽  
pp. 8764-8768 ◽  
Author(s):  
Mingwen Zhao ◽  
Yueyuan Xia ◽  
Xiangdong Liu ◽  
Zhenyu Tan ◽  
Boda Huang ◽  
...  
Keyword(s):  
First Principles ◽  
Surface States ◽  
First Principles Calculations ◽  
Atomic Structures

scholarly journals Spin-polarized two-dimensional electron/hole gases on LiCoO$_2$ layers.

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Santosh Kumar Radha ◽  
Walter R. L. Lambrecht
Keyword(s):  
First Principles ◽  
Tight Binding ◽  
Surface States ◽  
Computational Results ◽  
First Principles Calculations ◽  
Dimensional Electron ◽  
Electron Hole ◽  
Spin Polarized ◽  
Binding Models ◽  
Bulk Band

First-principles calculations show the formation of a 2D spin polarized electron (hole) gas on the Li (CoO_22) terminated surfaces of finite slabs down to a monolayer, in remarkable contrast with the bulk band structure, which is stabilized by Li donating its electron to the CoO_22 layer forming a Co-d-t_{2g}^6d−t2g6 insulator. By mapping the first-principles computational results to a minimal tight-binding models corresponding to a non-chiral 3D generalization of the quadripartite Su-Schrieffer-Heeger (SSH4) model and symmetry analysis, we show that these surface states have topological origin.

scholarly journals Obvious Surface States Connecting to the Projected Triple Points in NaCl’s Phonon Dispersion

2021 ◽  
Vol 9 ◽  
Author(s):  
Li Zhang ◽  
Fang Fang ◽  
Lixin Cheng ◽  
Huiming Lin ◽  
Kai Wang
Keyword(s):  
Computer Technology ◽  
Triple Point ◽  
First Principles ◽  
Phonon Dispersion ◽  
Surface States ◽  
Theoretical Chemistry ◽  
First Principles Calculations ◽  
Nodal Lines ◽  
Topological Materials ◽  
Speed And Accuracy

With the development of computer technology and theoretical chemistry, the speed and accuracy of first-principles calculations have significantly improved. Using first-principles calculations to predict new topological materials is a hot research topic in theoretical and computational chemistry. In this work, we focus on a well-known material, sodium chloride (NaCl), and propose that the triple point (TP), quadratic contact triple point (QCTP), linear and quadratic nodal lines can be found in the phonon dispersion of NaCl with Fm3¯ m type structure. More importantly, we propose that the clear surface states connected to the projected TP and QCTP are visible on the (001) surface. It is hoped that further experimental investigation and verification for these properties as mentioned above.

Light Emission Induced by the Indium Distribution in InGaN Nanowires

2013 ◽  
Vol 815 ◽  
pp. 148-153
Author(s):  
Jun Jie Shi ◽  
Tie Cheng Zhou ◽  
Hong Xia Zhong ◽  
Xin He Jiang ◽  
Pu Huang
Keyword(s):  
First Principles ◽  
Electronic Structures ◽  
Light Emission ◽  
Optical Transition ◽  
Laser Diodes ◽  
Optoelectronic Devices ◽  
Surface States ◽  
First Principles Calculations ◽  
Light Emitting ◽  
Interband Optical Transition

The InGaN nanowires (NWs) have attracted intense attention for their huge potential in applications such as light emitting diodes, laser diodes and solar cells. Although lots of work are focused on improving their optical performance, little is known about the influence of the In distribution and the surface states on the microscopic light emission mechanism. In order to give an atomic level understanding, we investigate the electronic structures of the wurtziteGa-rich InGaN NWs with different In distributions using first-principles calculations. We find that the In-atoms are apt to distribute on the surface of the NWs and the short surface In-N chains can be easily formed. For the unsaturated NWs, several new bands are induced by the surface states, which can be modified by the surface In microstructures. The randomly formed surface In-N chains can highly localize the electrons/holes at the band edges and dominate the interband optical transition. For the saturated NWs, the band edges are determined by the inner atoms. Our work is useful to improve the performance of the InGaN NW-based optoelectronic devices.

The passivation of PEA+ to MAPbI3 (110) surface states by first-principles calculations

2020 ◽  
Author(s):  
Wei Hu ◽  
Ying Tian ◽  
Hong-Tao Xue ◽  
Wen-Sheng Li ◽  
Fu-Ling Tang
Keyword(s):  
First Principles ◽  
Surface States ◽  
First Principles Calculations

scholarly journals Passivating Surface States on Water Splitting Cuprous Oxide Photocatalyst with Bismuth Decoration

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4156
Author(s):  
Yuhong Huang ◽  
Hongkuan Yuan ◽  
Hong Chen
Keyword(s):  
Visible Light ◽  
First Principles ◽  
Positive Response ◽  
Surface States ◽  
Photogenerated Electron ◽  
Redox Potentials ◽  
First Principles Calculations ◽  
Visible Light Photocatalyst ◽  
Electron Holes ◽  
Excited Transition

To enhance the visible light photocatalystic activity of Cu 2 O(100) surface, we performed first-principles calculations on the structural, electronic and optical properties of a bismuth (Bi)-decorated Cu 2 O(100) surface (Bi@Cu 2 O(100)). It is shown that the Bi prefer to be loaded to the hollow sites among four surface oxygen atoms and tend to individual dispersion instead of aggregating on the surface due to the lowest formation energy and larger distance between two Bi atoms at the surface than the Bi clusters; the coverage of around 0.25 monolayer Bi atoms can effectively eliminate the surface states and modify the band edges to satisfy the angular momentum selection rules for light excited transition of electrons, and the loaded Bi atoms contribute to the separation of photogenerated electron-holes. The relative positions between the band edges and the redox potentials are suitable for photocatalytic hydrogen production from the redox water, and moreover, the optical absorption spectrum indicates a positive response of the Bi 0 . 25 @Cu 2 O(100) to visible light, implying that the Bi 0 . 25 @Cu 2 O(100) is a promising visible light photocatalyst.

Topological states modulation of Bi and Sb thin films by atomic adsorption

2015 ◽  
Vol 17 (5) ◽  
pp. 3577-3583 ◽  
Author(s):  
Dongchao Wang ◽  
Li Chen ◽  
Hongmei Liu ◽  
Xiaoli Wang ◽  
Guangliang Cui ◽  
...  
Keyword(s):  
Thin Films ◽  
First Principles ◽  
Surface States ◽  
First Principles Calculations ◽  
Atomic Adsorption ◽  
Topological States ◽  
Topological Surface

Based on first-principles calculations, we systematically investigated the topological surface states of Bi and Sb thin films of 1–5 bilayers in (111) orientation without and with H(F) adsorption, respectively.

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