The European Physical Journal D最新文献

In this study, we investigated the electrical and thermoelectric properties of the zinc porphyrin dimer and the double-dimer zinc porphyrin molecular junctions using density functional theory (DFT) combined with the non-equilibrium Green’s function method. Our results demonstrate that the electronic transport and thermoelectric properties of these junctions can be significantly improved in the presence of another dimer. By adding a new zinc porphyrin dimer, the electrical conductance (G) increased up to an order of magnitude and showed further enhancement in the Seebeck coefficient for a good range of Fermi energies. However, the situation is the opposite in the case of the structure of zinc porphyrin dimer without any additives. These results imply that through modifications in the molecular configuration, there exists a promising potential for enhancing the figure of merit (ZT) value, thereby these systems can be potentially utilized to increase the opportunities for versus application in molecular-scale thermoelectric energy generators we conducted a comparative analysis between the zinc porphyrin dimer and the double-dimer zinc porphyrin molecular junctions.

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Zinc porphyrin dimers-based molecular wire

In recent years, there has been a growing global interest in ultra-wide bandgap semiconductor materials, with aluminium nitride emerging as a particularly promising material. Using density-functional theory (DFT) at the CAM-B3LYP/6-311G(3d,2p) basis set level, we have systematically optimized the geometries of the (AlN)₁₂ cluster. Furthermore, the structural and thermodynamic changes of these clusters under the external electric field (EEF) were investigated. When the external electric field intensity increased the energy gap decreases continuously, infrared spectral analysis showed an obvious Stark effect, and the molecular structure showed significant alterations. Additionally, the study examined orbital compositions and excitation properties of twenty excited states using time-dependent density-functional theory (TD-DFT). The results indicated a decrease in excitation energy with increasing EEF, resulting in longer wavelengths and red-shifted spectral. These findings provide an opportunity to precisely modulate the electronic properties of (AlN)₁₂ cluster by controlling the strength and direction of the EEF, opening up more possibilities for their application in photoelectronic devices.

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Appreciable effort is currently committed to designing suitable organometallic precursors for fabrication of metallic nanostructures with focused electron beam induced deposition (FEBID)—a direct write method with high potential for 3D patterning. In this context, the initial interaction of the potential precursor with low energy electrons is critical and the extent of electron-induced ligand loss determines the composition of the resulting deposits. Specifically of interest are gold-containing precursors, as the optoelectronic properties of gold provide potential for a variety of plasmonic and light enhancing applications of 3D nanostructures. Here, we study low energy electron-induced fragmentation of CF₃AuCNC(CH₃)₃ through dissociative ionization (DI) and dissociative electron attachment (DEA) in the gas phase under single collision conditions and under conditions where collisional stabilization is provided. We further compare the fragmentation patterns observed under these conditions with the composition of deposits formed from this precursor under FEBID conditions. In DI, a significant difference in relative intensities is found under single collision conditions as compared to conditions where collisional stabilization is provided, while under both these conditions, only the same DEA channel is open. Comparison with the composition of deposits formed under FEBID conditions shows that the initial electron-induced fragmentation processes are not directly reflected in the deposit’s composition. Rather, we expect these to determine the initial composition of immobilized fragments, while the final composition of the deposit is determined by electron-induced secondary and tertiary reactions caused by further irradiation after immobilization.

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The performance degradation of reference-frame-independent measurement-device-independent quantum key distribution (RFI-MDI-QKD) protocol caused by the finite key size effect impedes its practical implementation. The protocol utilizes the double-scanning method, which makes it possible to precisely estimate both the counts of single-photon pairs and the phase-flip error. This method effectively counteracts the statistical fluctuation brought on by the finite key size effect. Based on this method, we propose a scheme in this work that substitutes heralded single-photon sources (HSPS) for weak coherent sources (WCS), and we compare the performance of the two schemes by calculating the key rate. The RFI-MDI-QKD using HSPS, according to the results of the simulation, has a lower key rate than the RFI-MDI-QKD using WCS, but it also has a longer transmission distance and a more noticeable improvement in transmission distance at larger rotation angles. Thus, we demonstrate that the RFI-MDI-QKD protocol, based on the double-scanning method and using HSPS, has promising future application potential.

Theoretical investigations of K-shell Δn?=?1 (1s?→?2l) dielectronic recombination (DR) of B-like Ar¹³⁺ ions are performed. The resonance energies, autoionization and radiative rates, as well as DR strengths, are obtained with inclusion of Breit and QED corrections using the Flexible Atomic Code. Furthermore, the differential cross sections, linear polarization, and polarization-dependent spectra for KLL DR process are presented for X-ray dielectronic satellite lines. The present results indicate the importance of high-order trielectronic and quadruelectronic recombination.

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