scholarly journals A Solid-State Fluorescence Switch Based on Triphenylethene-Functionalized Dithienylethene With Aggregation-Induced Emission

2021 ◽  
Vol 9 ◽  
Author(s):  
Haining Zhang ◽  
Xiaoxiao Hu ◽  
Huijuan Zhu ◽  
Limin Shen ◽  
Congmin Liu ◽  
...  
Keyword(s):  
Solid State ◽  
Visible Light ◽  
Density Functional ◽  
Uv Light ◽  
Functional Theory ◽  
Aggregation Induced Emission ◽  
H Nmr ◽  
Chemical Structures ◽  
Fluorescence Switch ◽  
The Density Functional Theory

The development of novel dithienylethene-based fluorescence switches in the aggregated state, and the solid state is highly desirable for potential application in the fields of optoelectronics and photopharmacology. In this contribution, three novel triphenylethene-functionalized dithienylethenes (1–3) have been designed and prepared by appending triphenylethene moieties at one end of dithienylethene unit. Their chemical structures are confirmed by 1H NMR, 13C NMR, and HRMS (ESI). They display good photochromic behaviors with excellent fatigue resistance upon irradiation with UV or visible light in Tetrahydrofuran (THF) solution. Before irradiation with UV light, they exhibit Aggregation Induced Emission (AIE) properties and luminescence behaviors in the solid state. Moreover, upon alternating irradiation with UV/visible light, they display effective fluorescent switching behaviors in the aggregated state and the solid state. The experimental results have been validated by the Density Functional Theory (DFT) calculations. Thus, they can be utilized as novel fluorescence switches integrated in smart, solid-state optoelectronic materials and photopharmacology.

Theoretical analysis of ammoniaborane and alkylammoniaborane at the solid state

2017 ◽  
Author(s):  
Mariano Méndez Chávez
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Theoretical Analysis ◽  
Gas Phase ◽  
Density Functional ◽  
Structural Parameters ◽  
Ammonia Borane ◽  
Functional Theory ◽  
The Density Functional Theory

This work deals with a benchmark for the calculation of the structural parameters of ammonia-borane and alkylammonia-borane at the solid state, using hybrid and GGA functionals in the framework of the Density Functional Theory as well as the use of Grimme's empirical dispersion. A comparison for some dimers of the aforementioned species, calculated at the gas-phase at the level MP2/aug-cc-pVTZ is discussed.

Theoretical analysis of ammoniaborane and alkylammoniaborane at the solid state

2017 ◽  
Author(s):  
Mariano Mendez Chavez
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Theoretical Analysis ◽  
Gas Phase ◽  
Density Functional ◽  
Structural Parameters ◽  
Ammonia Borane ◽  
Functional Theory ◽  
The Density Functional Theory

This work deals with a benchmark for the calculation of the structural parameters of ammonia-borane and alkylammonia-borane at the solid state, using hybrid and GGA functionals in the framework of the Density Functional Theory as well as the use of Grimme's empirical dispersion. A comparison for some dimers of the aforementioned species, calculated at the gas-phase at the level MP2/aug-cc-pVTZ is discussed.

Structure Study of ZnO:Eu with the Supercell Method

2010 ◽  
Vol 9 ◽  
pp. 25-30 ◽  
Author(s):  
A. Blanca-Romero ◽  
A. Flores-Riveros ◽  
J.F. Rivas-Silva
Keyword(s):  
Density Functional Theory ◽  
Rare Earth ◽  
Solid State ◽  
Density Functional ◽  
Cell Model ◽  
Structure Study ◽  
Functional Theory ◽  
Kondo Resonance ◽  
Super Cell ◽  
The Density Functional Theory

One of the interests on the study of doped materials with rare earths in their bulk or nanoscale size is owing to the enhancement of the intensity of light in their photoluminescence when a lanthanide exists in a receptor material, as ZnO in our case. Until now, one of the most useful theories for calculations of electronic properties in molecular and solid state systems is the Density Functional Theory (DFT), which is not capable to manage well the presence of high localized electrons, as in lanthanide compounds in general and the doped case in particular. We propose to study these materials with super cell model using some correction to the standard calculations. For this goal, we employ the WIEN2k [1] code using the LDA+U approximation to take into account the strong correlation of the f electrons coming from the lanthanide. We emphasise the study of deformation due to the presence of Eu ion in the structure of host material, optimizing the position of neighboring Oxygen atoms. This deformation has been related to Kondo Resonance [2] appearing around the Fermi Energy of the compound, due to hybridization [3] among the f electrons from rare earth and neighboring oxygen levels.

The Modification of Anatase TiO2 (001) Surface by N or S Atom: A DFT Investigation

2014 ◽  
Vol 941-944 ◽  
pp. 588-592
Author(s):  
Zong Bao Li ◽  
Xia Wang
Keyword(s):  
Density Functional Theory ◽  
Visible Light ◽  
Electronic Structures ◽  
Density Functional ◽  
Light Response ◽  
Functional Theory ◽  
Visible Light Response ◽  
The Density Functional Theory ◽  
Elemental Doping ◽  
Formation Energies

The electronic of S-doped and N-doped anatase TiO2(001) surfaces were investigated using the density functional theory (DFT). Substitutional and interstitial configurations of N and S atoms doped in anatase TiO2(001) surface and sub-surface at different sites were considered and all the formation energies were obtained. The perfect strutures of atoms doping were obstained by formation energies comparisions. The electronic structures of the results indicated that the elemental doping has much more efficient and stable photocatalyst than the pristine one, which narrowed the band gap of TiO2and improved its visible-light response activity.

First-Principle Study of Electronic Structure and Enhanced Visible-Light Photocatalytic Activity of Anatase TiO2 through C and F Codoping

2013 ◽  
Vol 746 ◽  
pp. 400-405 ◽  
Author(s):  
Zong Bao Li ◽  
Xia Wang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Density Functional ◽  
Light Response ◽  
Functional Theory ◽  
Visible Light Photocatalytic Activity ◽  
Visible Light Response ◽  
The Density Functional Theory ◽  
Visible Light Photocatalytic

The large intrinsic band gap in TiO2has hindered severely its potential application for visible-light irradiation, while anion doping has led to decreases in visible-light photocatalytic activity in spite of narrowing the host band gap. In this study, we have used cation-passivated codoping of (C, F), (C, 2F) and (2C, F) to modify the band edges of anatase TiO2to extend absorption to longer visible-light wavelegenths using the density functional theory based on GGA + U method. The results indicate that the codoping of C/F=1/1 cases have much more efficient and stable photocatalyst than pristine one and the others, which narrow the band gaps and realize the visible-light response activities.

scholarly journals Disinfection mechanism of the photocatalytic activity of SnO2 thin films against Candida albicans, proposed from the experimental and simulated perspective

2021 ◽  
Author(s):  
Alejandro Faudoa-Arzate ◽  
Javier Camarillo-Cisneros ◽  
Alva Rocío Castillo-González ◽  
María Alejandra Favila-Pérez ◽  
Renee Joselin Sáenz-Hernández ◽  
...  
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Candida Albicans ◽  
Density Functional ◽  
Uv Light ◽  
Functional Theory ◽  
Colony Forming Units ◽  
The Density Functional Theory ◽  
Important Health ◽  
Sno2 Thin Films

Background: Nosocomial infections are important health problems and a cause of complications and death in hospitalized patients. This problem should be solved from the preventive angle, avoiding the spread of infections by designing disinfection methods based on the photocatalytic activity of semiconductor materials like Tin Oxide (SnO2). Methods: Antimicrobial activity of UV light was tested using Candida albicans ATCC10231 inoculation of SnO2 thin films by counting colony forming units (UFC). Interaction of UV light with SnO2 was analyzed by the Density Functional Theory (DFT) and the extension to Hubbard model (DFT+U) schemes to predict the electrons behavior in a subatomic level. Results: After exposure to UV light, C. albicans had a reduction of 36.5% of viable cells, and when SnO2 was included, cells were reduced by 60.2%. Measures of the electronics structure obtained by the first principle calculations under the DFT and DFT+U schemes showed that O-p orbitals mediate the oxidation process in the bulk semiconductor. By including the surface effects when cleaving the (1 0 0) plane, the three orbitals O-p, Sn-p, and Sn-s are the mediators. Conclusions: SnO2 films are promising antimicrobial coatings because UV light has a synergic activity with thin films, resulting in a faster disinfection.

scholarly journals Polymorphs of Rb3ScF6: X-ray and Neutron Diffraction, Solid-State NMR, and Density Functional Theory Calculations Study

2021 ◽  
Vol 60 (8) ◽  
pp. 6016-6026
Author(s):  
Aydar Rakhmatullin ◽  
Maxim S. Molokeev ◽  
Graham King ◽  
Ilya B. Polovov ◽  
Konstantin V. Maksimtsev ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Neutron Diffraction ◽  
Solid State Nmr ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
X Ray

scholarly journals Strain Investigation on Spin-Dependent Transport Properties of γ-Graphyne Nanoribbon Between Gold Electrodes

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yun Li ◽  
Xiaobo Li ◽  
Shidong Zhang ◽  
Liemao Cao ◽  
Fangping Ouyang ◽  
...  
Keyword(s):  
Transport Properties ◽  
High Performance ◽  
Density Functional ◽  
Strain Engineering ◽  
Molecular Junctions ◽  
Spin Splitting ◽  
Functional Theory ◽  
Spin Dependent Transport ◽  
The Density Functional Theory ◽  
Dependent Transport

AbstractStrain engineering has become one of the effective methods to tune the electronic structures of materials, which can be introduced into the molecular junction to induce some unique physical effects. The various γ-graphyne nanoribbons (γ-GYNRs) embedded between gold (Au) electrodes with strain controlling have been designed, involving the calculation of the spin-dependent transport properties by employing the density functional theory. Our calculated results exhibit that the presence of strain has a great effect on transport properties of molecular junctions, which can obviously enhance the coupling between the γ-GYNR and Au electrodes. We find that the current flowing through the strained nanojunction is larger than that of the unstrained one. What is more, the length and strained shape of the γ-GYNR serves as the important factors which affect the transport properties of molecular junctions. Simultaneously, the phenomenon of spin-splitting occurs after introducing strain into nanojunction, implying that strain engineering may be a new means to regulate the electron spin. Our work can provide theoretical basis for designing of high performance graphyne-based devices in the future.

scholarly journals Electron-phonon interaction in In-induced √7 ×√3 structures on Si(111) from first-principles

2021 ◽  
Author(s):  
I. Yu. Sklyadneva ◽  
Rolf Heid ◽  
Pedro Miguel Echenique ◽  
Evgueni Chulkov
Keyword(s):  
Density Functional Theory ◽  
Double Layer ◽  
First Principles ◽  
Linear Response ◽  
Density Functional ◽  
Single Layer ◽  
Phonon Interaction ◽  
Functional Theory ◽  
Electron Phonon Interaction ◽  
The Density Functional Theory

Electron-phonon interaction in the Si(111)-supported rectangular √(7 ) ×√3 phases of In is investigated within the density-functional theory and linear-response. For both single-layer and double-layer √(7 ) ×√3 structures, it...

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