scholarly journals The electronic states of ITO–MoS2: Experiment and theory

2021 ◽  
Author(s):  
Oscar A. López-Galán ◽  
Manuel Ramos ◽  
John Nogan ◽  
Alejandro Ávila-García ◽  
Torben Boll ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Density Functional ◽  
Schottky Barrier Height ◽  
Energy Levels ◽  
Electronic States ◽  
Carrier Injection ◽  
Functional Theory ◽  
Orbital Interactions

AbstractWe report a combination of experimental results with density functional theory (DFT) calculations to understand electronic structure of indium tin oxide and molybdenum disulfide (ITO–MoS2) interface. Our results indicate ITO and MoS2 conform an n-type Schottky barrier of c.a. − 1.0 eV due to orbital interactions; formation of an ohmic contact is caused by semiconducting and metal behavior of ITO as a function of crystal plane orientation. ITO introduces energy levels around the Fermi level in all interface models in the Γ-Μ-Κ-Γ path. The resulted Van der Waals interface and the values of Schottky barrier height enhance electron carrier injection. Graphical abstract

Tuning the Schottky barrier height in a multiferroic In2Se3/Fe3GeTe2 van der Waals heterojunction

Nanoscale ◽  
2021 ◽  
Author(s):  
Maria Javaid ◽  
Patrick David Taylor ◽  
Sherif Abdulkader Tawfik ◽  
Michelle Jeanette Sapountzis Spencer
Keyword(s):  
Density Functional Theory ◽  
Electronic Properties ◽  
Schottky Barrier ◽  
Barrier Height ◽  
Density Functional ◽  
Schottky Barrier Height ◽  
Van Der Waals ◽  
Ferroelectric Material ◽  
Functional Theory ◽  
Significant Interest

The ferroelectric material In2Se3 is currently of significant interest due to its built-in polarisation characteristics that can significantly modulate its electronic properties. Here we employ density functional theory to determine...

scholarly journals Optoelectronic Properties of Ultrathin Indium Tin Oxide Films: A First-Principle Study

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 30
Author(s):  
Xiaoyan Liu ◽  
Lei Wang ◽  
Yi Tong
Keyword(s):  
Film Thickness ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Density Functional ◽  
Optoelectronic Properties ◽  
Surface Strain ◽  
Strain Effect ◽  
First Principle ◽  
Electrical Resistivities ◽  
Ito Films

First-principle density functional theory simulations have been performed to predict the electronic structures and optoelectronic properties of ultrathin indium tin oxide (ITO) films, having different thicknesses and temperatures. Our results and analysis led us to predict that the physical properties of ultrathin films of ITO have a direct relation with film thickness rather than temperature. Moreover, we found that a thin film of ITO (1 nm thickness) has a larger absorption coefficient, lower reflectivity, and higher transmittance in the visible light region compared with that of 2 and 3 nm thick ITO films. We suggest that this might be due to the stronger surface strain effect in 1 nm thick ITO film. On the other hand, all three thin films produce similar optical spectra. Finally, excellent agreement was found between the calculated electrical resistivities of the ultrathin film of ITO and that of its experimental data. It is concluded that the electrical resistivities reduce along with the increase in film thickness of ITO because of the short strain length and limited bandgap distributions.

scholarly journals Defect Processes in Halogen Doped SnO2

2021 ◽  
Vol 11 (2) ◽  
pp. 551
Author(s):  
Petros-Panagis Filippatos ◽  
Nikolaos Kelaidis ◽  
Maria Vasilopoulou ◽  
Dimitris Davazoglou ◽  
Alexander Chroneos
Keyword(s):  
Electronic Properties ◽  
Tin Oxide ◽  
Density Functional ◽  
Structural Changes ◽  
High Dielectric Constant ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Optical And Electronic Properties ◽  
High Dielectric ◽  
Gap States

In the present study, we performed density functional theory calculations (DFT) to investigate structural changes and their impact on the electronic properties in halogen (F, Cl, Br, and I) doped tin oxide (SnO2). We performed calculations for atoms intercalated either at interstitial or substitutional positions and then calculated the electronic structure and the optical properties of the doped SnO2. In all cases, a reduction in the bandgap value was evident, while gap states were also formed. Furthermore, when we insert these dopants in interstitial and substitutional positions, they all constitute a single acceptor and donor, respectively. This can also be seen in the density of states through the formation of gap states just above the valence band or below the conduction band, respectively. These gap states may contribute to significant changes in the optical and electronic properties of SnO2, thus affecting the metal oxide’s suitability for photovoltaics and photocatalytic devices. In particular, we found that iodine (I) doping of SnO2 induces a high dielectric constant while also reducing the oxide’s bandgap, making it more efficient for light-harvesting applications.

scholarly journals Unraveling the electrochemical and spectroscopic properties of neutral and negatively charged perylene tetraethylesters

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christian Wiebeler ◽  
Joachim Vollbrecht ◽  
Adam Neuba ◽  
Heinz-Siegfried Kitzerow ◽  
Stefan Schumacher
Keyword(s):  
Absorption Spectra ◽  
Density Functional ◽  
Energy Levels ◽  
Spectroscopic Properties ◽  
Absorption Bands ◽  
Functional Theory ◽  
Vertical Excitation ◽  
Hartree Fock ◽  
Tauc Plot ◽  
Electrochemical Approach

AbstractA detailed investigation of the energy levels of perylene-3,4,9,10-tetracarboxylic tetraethylester as a representative compound for the whole family of perylene esters was performed. It was revealed via electrochemical measurements that one oxidation and two reductions take place. The bandgaps determined via the electrochemical approach are in good agreement with the optical bandgap obtained from the absorption spectra via a Tauc plot. In addition, absorption spectra in dependence of the electrochemical potential were the basis for extensive quantum-chemical calculations of the neutral, monoanionic, and dianionic molecules. For this purpose, calculations based on density functional theory were compared with post-Hartree–Fock methods and the CAM-B3LYP functional proved to be the most reliable choice for the calculation of absorption spectra. Furthermore, spectral features found experimentally could be reproduced with vibronic calculations and allowed to understand their origins. In particular, the two lowest energy absorption bands of the anion are not caused by absorption of two distinct electronic states, which might have been expected from vertical excitation calculations, but both states exhibit a strong vibronic progression resulting in contributions to both bands.

Research Optical Characteristics of H2S Molecule Adsorption on Agn (n=2,4,6) Clusters

2013 ◽  
Vol 321-324 ◽  
pp. 499-502
Author(s):  
Hong Zhou ◽  
Jun Feng Wang ◽  
Jun Qing Wen ◽  
Wei Bin Cheng ◽  
Jun Fei Wang
Keyword(s):  
Density Functional Theory ◽  
Infrared Spectrum ◽  
Density Functional ◽  
Global Minimum ◽  
Electronic States ◽  
Binding Energies ◽  
Optical Characteristics ◽  
Functional Theory ◽  
Calculation Results ◽  
Planar Geometries

Density-functional theory has been used to calculate the energetically global-minimum geometries and electronic states of AgnH2S (n=2, 4, 6) clusters. The lowest-energy structures of Ag2, Ag4, Ag6, Ag2H2S, Ag4H2S and Ag6H2S clusters were obtained, respectively. The calculation results show that the lowest-energy structures of Ag2, Ag4and Ag6clusters are planar geometries. The binding energies of Agn(n=2, 4, 6) clusters are gradually increasing in our calculations. Compare the infrared spectrum peaks of Ag4cluster with that of Ag6cluster, which show that the peaks shift to shortwave. After adsorption, we found that the peaks shift to shortwave by comparison.

scholarly journals Density functional theory study on the atomic structure and electronic states of Cu(100) (2×22)R45°-O surface

2005 ◽  
Vol 54 (11) ◽  
pp. 5350
Author(s):  
Cai Jian-Qiu ◽  
Tao Xiang-Ming ◽  
Chen Wen-Bin ◽  
Zhao Xin-Xin ◽  
Tan Ming-Qiu
Keyword(s):  
Density Functional Theory ◽  
Atomic Structure ◽  
Density Functional ◽  
Electronic States ◽  
Density Functional Theory Study ◽  
Functional Theory

scholarly journals Taguchi-Assisted Optimization Technique and Density Functional Theory for Green Synthesis of a Novel Cu-MOF Derived From Caffeic Acid and Its Anticancerious Activities

2021 ◽  
Vol 9 ◽  
Author(s):  
Malihe Zeraati ◽  
Ali Mohammadi ◽  
Somayeh Vafaei ◽  
Narendra Pal Singh Chauhan ◽  
Ghasem Sargazi
Keyword(s):  
Density Functional Theory ◽  
Caffeic Acid ◽  
Density Functional ◽  
Energy Levels ◽  
Optimization Technique ◽  
Nitrogen Adsorption ◽  
High Porosity ◽  
Anticancer Activities ◽  
Functional Theory ◽  
Sem Analyses

In this paper, we have reported an innovative greener method for developing copper-metal organic frameworks (Cu-MOFs) using caffeic acid (CA) as a linker extracted from Satureja hortensis using ultrasonic bath. The density functional theory is used to discuss the Cu-MOF-binding reaction mechanism. In order to achieve a discrepancy between the energy levels of the interactive precursor orbitals, the molecules have been optimized using the B3LYP/6–31G method. The Taguchi method was used to optimize the key parameters for the synthesis of Cu-MOF. FT-IR, XRD, nitrogen adsorption, and SEM analyses are used to characterize it. The adsorption/desorption and SEM analyses suggested that Cu-MOF has a larger surface area of 284.94 m2/g with high porosity. Cu-MOF has shown anticancer activities against the human breast cancer (MDA-MB-468) cell lines, and it could be a potent candidate for clinical applications.

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