Search results for "ELECTRONIC PROPERTIES"
showing 10 items of 96 documents
Electronic Properties of Point Defects in Metals
1982
Recent progress in electronic structure and related properties of point defects in metals is reviewed. Topics discussed include transition metal impurities in a non-magnetic host, construction of potential energy surfaces from effective-medium theories, trapping of light interstitials, and pair potential in metals.
Evolution of the electronic properties of graded poly(thienylene vinylene)-poly(pyrrylene vinylene) mixed copolymers
1993
Abstract We present a valence effective Hamiltonian (VEH) theoretical investigation of the evolution of the electronic properties of poly(thienylene vinylene)-poly(pyrrylene vinylene) mixed copolymers as a function of the unit cell content on the basis of ab initio 3–21G∗ and 3–21G optimized geometries. As a consequence of the strong localization of the LUCO both electron affinity and bandgap deviate from a linear dependence, and only the ionization potential presents the expected values.
Comparativeab initiostudy of half-Heusler compounds for optoelectronic applications
2010
For the advancement of optoelectronic applications, such as thin-film solar cells or laser diodes, there is a strong demand for new semiconductor materials with tailored structural and electronic properties. The eight-electron half-Heusler compounds include many promising materials with a big variety of lattice constants and band gaps. So far only a small number of them have been investigated. With the help of ab initio calculations, we have studied all possible configurations of ternary 1:1:1 compounds in the half-Heusler structure. We have investigated 648 half-Heusler materials, including compounds of the types I-I-VI, I-II-V, I-III-IV, II-II-IV, and II-III-III. For all compounds, we hav…
Optical and electronic properties of graphene nanoribbons upon adsorption of ligand-protected aluminum clusters
2014
We have carried out first-principles calculations to investigate how the electronic and optical features of graphene nanoribbons are affected by the presence of atomic clusters. Aluminum clusters of different sizes and stabilized by organic ligands were deposited on graphene nanoribbons from which the energetic features of the adsorption plus electronic structure were treated within density-functional theory. Our results point out that, depending on their size and structure shape, the clusters perturb distinctively the electronic properties of the ribbons. We suggest that such selective response can be measured through optical means revealing that graphene nanoribbons can work as an efficie…
On the Shape-Selected, Ligand-Free Preparation of Hybrid Perovskite (CH3NH3PbBr3) Microcrystals and Their Suitability as Model-System for Single-Crys…
2021
Hybrid perovskite materials are one of the most promising candidates for optoelectronic applications, e.g., solar cells and LEDs, which can be produced at low cost compared to established materials. Although this field of research has seen a huge upsurge in the past decade, there is a major lack in understanding the underlying processes, such as shape-property relationships and the role of defects. Our aerosol-assisted synthesis pathway offers the possibility to obtain methylammonium lead bromide (MAPbBr3 ) microcrystals from a liquid single source precursor. The differently shaped particles are aligned on several substrates, without using a directing agent or other additives. The obtained …
Orientational preferences of aromatic guests in dimeric capsules of tetraurea calix[4]arenes—MD and NMR studies
2006
Molecular dynamics (MD) simulations have been performed for complexes of a dimeric capsule of a tetraurea calixarene with a series of twelve aromatic guests. A distinct orientational preference and a restriction of the internal mobility was found which depend on the size and electronic properties of the guests. The results are in agreement with the CIS values obtained from (1)H NMR spectroscopic measurements and with complexation selectivities obtained by competition experiments.
3-(2-Pyridyl)-[1,2,3]triazolo[1,5-a]pyridines. An experimental and theoretical (DFT) study of the ring-chain isomerization
2005
An experimental (1H NMR) and theoretical (DFT) study of the ring-chain-ring isomerization of 3-(2-pyridyl)-[1,2,3]triazolo[1,5-a]pyrid-7-yl derivatives (A) into 6-{[1,2,3]triazolo[1,5-a]pyrid-3-yl}-2-pyridyl derivatives (B) has been carried out. Based on the calculations, a mechanism of several steps will be proposed. The experimental results as well as the calculations lead to the conclusion that the A-B ratio depends on the electronic properties of the substituents. © The Royal Society of Chemistry 2005.
Role of Molybdenum on the Electronic Properties of Passive Films on Stainless Steels
2020
Potentiostatic polarization of different stainless steel grades with a mirror surface finishing was performed in order to investigate the role of Mo on stainless steels corrosion behaviour. In the attempt to gain more insight into transpassive dissolution mechanism, passive films were grown in neutral aqueous solution (pH ∼ 7) at different polarizing potentials ranging from passive to transpassive conditions. According to the photoelectrochemical characterization, Cr dissolution occurs even at low polarizing potentials in the case of AISI 304L, while higher band gap values were obtained for passive films grown on austenitic 316L and duplex SSs. Capacitance measurements suggest that the flat…
Mott-Schottky analysis of differential capacitance data of passive-film electrolyte junctions. Is it really providing correct physical insights on th…
2009
AB Initio Calculations of CUN@Graphene (0001) Nanostructures for Electrocatalytic Applications
2018
Funding from European Union’s Horizon 2020 Research and Innovation Programme project under grant agreement No. 768789 is greatly acknowledged.