Electronic structures and charge transport mobilities in hybrid organic-inorganic mixed Sn-Pb alloyed perovskites.

Electronic structure and transport properties of sol-gel-derived high-entropy Ba(Zr0.2Sn0.2Ti0.2Hf0.2Nb0.2)O3 thin films

Density functional theory (DFT) calculations were performed using a MPWB1K functional to interpret the charge transport (CT) properties of stacked annelated β-trithiophene molecules. The goal was to help understand how the chemical composition, face-to-face stacking, intra- and intermolecular correlations, and the applied electric field affect the CT properties of this organic semiconductor compared with those of the edge-to-face "herringbone" motif. The variations in the frontier molecular orbitals, energy gap, nonadiabatic electron attachment energies (EAE), and vertical detachment energies (VDE) were investigated under an external electric field as a function of the number of stacked layers (n). Two possible CT pathways, monomer-to-monomer (MM) and dimer-to-dimer (DD) transports, were postulated to determine the charge carrier conductivities of these molecules. The results highlight that the intermolecular electronic couplings and electrostatic interactions can significantly affect the stacking geometry, even in more extended structures; displaced stacks with smaller interlayer spacing resulted in more compact stacking and, thus, higher CT efficiency; face-to-face stacking geometries can help to reduce the energy gap and VDE. Despite the fact that common thiophene-based oligomers adopting edge-to-face herringbone motifs exhibited p-type (hole-transporting) characters, the face-to-face stacked models based on annelated β-trithiophenes exhibited remarkably increased n-type (electron-transporting) performances. The electric field in the z-direction produced a small influence on the DD charge transport, whereas both electron and hole mobilities decreased dramatically in the MM case. More importantly, in MM charge transport, the electric field increases the hole mobility so that it is higher than that of the electron.

Future developments of the thermoelectric technologies based on conducting polymer require to find n-type polymers with performance, especially electrical conductivity, comparable to the one of the state-of-the-art p-type conducting polymers. In this regard, naphthalenediimide based donor–acceptor copolymers have appeared as promising candidates. The backbone of the polymer can be engineered to control the electronic structure and the morphology of the chains in order to maximize both the charge carrier density and mobility. However, at the moment a complete theoretical insight from electronic structures to charge transport is missing. Here, we use a multiscale theoretical framework to study naphthalenediimide based donor–acceptor copolymers where the donor π-conjugated dithienylvinylene moieties are replaced by π non-conjugated dithienylethane in various amounts, and we show that this approach is in position to rationalize many experimental data. The resulting gradual change in electronic structure of polymer chains is investigated by the density functional theory and correlated with experimental absorption spectra. The morphology of a polymer film is studied by means of molecular dynamics simulations, showing that an extended network of inter-chain π–π stacking is preserved upon introduction of non-conjugated units in the polymer backbone. This finding is supported by a subsequent calculation of the charge transport, which shows only a moderate impact of the morphology on the mobility, while the experimental data can be retrieved by considering the effect of the π non-conjugated moiety on the electronic structure. Such a multiscale description of conducting polymers paves the way toward fully theoretical design of future high performances materials.

Based on the survey data of the waters of Jiaozhou Bay in May, August and October 1992, the change of Pb content and its deposition process in the surface and bottom waters of Jiaozhou Bay were studied. According to the definition and model of Dongfang Yang’s content changing degree, the variation of Pb content at surface and bottom and of Pb content transported by main sea current formed a peak line in the southeast waters of Jiaozhou Bay. The Pb content on the surface reached its peak in August. From May to August, Dongfang Yang’s content changing degree was 79.84°. However, from August to October, it was -85.29°. Specifically, in surface water, Dongfang Yang’s content changing degree from May to August was 62.48°. From August to October, Dongfang Yang’s content changing degree was -39.00°. In the bottom water, Dongfang Yang’s content changing degree from May to August was 70.41°. From August to October, Dongfang Yang’s content changing degree was -80.03°. It indicates that the change of Pb content in surface nearshore waters passed through by the main sea current was determined by the change of Pb content transported by the current. The change of Pb content in surface seawater through the change of ocean currents increases or decreases the increase or decrease of Pb content in surface water —The Pb content of surface water increased or decreased with the increase or decrease of Pb content transported by main sea currents. The Pb content temporal variation in the surface and bottom of the southeastern waters of Jiaozhou Bay from May to October reveals the Pb content settling law: With the increase of Pb content in surface water, the Pb content in bottom water rose faster than that in surface water. When the Pb content in surface water decreased, the Pb content in bottom water decreased much faster than that in surface water. Therefore, the change mechanism of surface and bottom water caused by source transport is proposed with the corresponding model block diagram and changing degree model of Pb content transported by ocean currents.

Understanding the impact of polymorphism on the electronic structures and charge transport properties of contorted hexabenzocoronene

Poly(3,4-ethylenedioxythiophene) (PEDOT) and its derivatives have emerged as critical materials in modern electronic applications due to their exceptional electrical conductivity, biocompatibility, and processability. This comprehensive review examines the state-of-the-art computational strategies employed for designing and optimizing PEDOT-based electrodes across various electronic applications. We systematically assess multiscale modeling approaches, from quantum mechanical calculations to macroscopic device simulations, including Density Functional Theory (DFT), atomistic and coarse-grained Molecular Dynamics (MD), Finite Element Method (FEM), and emerging Machine Learning/Artificial Intelligence techniques. The review elucidates how these computational methods provide critical insights into PEDOT’s electronic structure, charge transport mechanisms, morphological characteristics, and interfacial behaviors. Particular emphasis is placed on structure-property relationships, including the aromatic-to-quinoid transition upon doping, the formation of polarons and bipolarons, the influence of π-π stacking on charge mobility, and the critical role of counterions in modulating electronic performance. We demonstrate their application in designing optimized electrodes for supercapacitors, organic electrochemical transistors, and flexible electronics. Finally, we analyze existing limitations in current computational frameworks and identify promising future directions, including multiscale integration, improved force fields, and quantum machine learning, that will accelerate the rational design of next-generation PEDOT-based materials with tailored functionalities. This review highlights the integration of computational strategies like DFT, MD, FEM, and ML/AI in designing PEDOT-based electrodes, emphasizing their role in understanding electronic structure, charge transport, morphology, and mechanical behavior. It explores recent advancements, applications, limitations, and future directions for optimizing PEDOT electrodes in electronic devices.

Investigation of the mixed electronic and ionic charge transport in metal halide perovskite semiconductors has been challenging due to undesirable ion migration effects that accompany electronic charge transport. This results in unusual nonlinear hysteretic characteristics and significant degradation of the device performance. Here, we develop an understanding of the ionic and electronic transport using a combination of charge transport, impedance spectroscopy, and lateral conductivity measurement to illustrate the difference in the vertical and lateral ionic and electrical conductivity in these classes of perovskite materials. Our measurements indicate that, although the vertical electronic charge transport remains unaffected by B-site compositional variation, the lateral conductivity increases by at least one order of magnitude upon substitution of Sn. Furthermore, the incorporation of Sn decreases both the vertical and lateral ionic conductivity. The observed decrease in the ionic conduction is attributed to the inherent Sn vacancy, which compensates for the ionic defects through the creation of neutral defect complexes. Our results provide clear guidance for developing strategies to control the ionic conductivity without significantly affecting the electronic conductivity, which can lead to stable hysteresis-free high-performance optoelectronic devices.

Reported in this paper is a quantum mechanics study on the electronic structure and contact resistance at the interfaces formed when an open-end single-walled carbon nanotube (CNT) is in end-contact with aluminum (Al) and palladium (Pd), respectively. The electronic structures are computed using a density functional theory (DFT), and the transmission coefficient is calculated using a nonequilibrium Green’s function (NEGF) in conjunction with the DFT. The current–voltage relation of the simulating cell is obtained by using the Landauer–Buttiker formula, from which the contact resistance can be determined. Our results show that the electronic structure and electron transport behavior are strongly dependent on the electrode. It is found that the CNT/Pd interface has a weaker bond than the CNT/Al interface. However, the CNT/Pd interface shows a lower electrical contact resistance.

Disorder-induced Anderson-like localization for bidimensional thermoelectrics optimization

Postecdysial mineralization in crustaceans involves the deposition of carbonate salts, such as calcium carbonate, to the organic matrix. Because of the resemblance between Pb2+ and Ca2+ , the present study was carried out to investigate whether Pb is incorporated into the new shell during postecdysial mineralization using the blue crab (Callinectes sapidus) as the model crustacean. It was hypothesized that injected Pb would be deposited in the shell via calcium transporters in the epidermis during the mineralization process. Postecdysial blue crabs were injected with two doses of 5 µg Pb/g wet weight each in lead acetate, and then Pb, Ca, and Mg contents were analyzed in the exoskeleton, while only Pb bioaccumulation was quantified for the hepatopancreas, gills, muscles, and hemolymph. The results showed a statistically nonsignificant increase in exoskeletal Pb content in Pb-treated crabs compared to control, suggesting that exoskeletal Pb may not be a sensitive proxy for aquatic Pb pollution. There was a significant decrease in Ca content in Pb-treated crabs, suggesting that Pb hindered the deposition of Ca to crab exoskeleton, thereby obstructing calcification. A trend of a decrease in exoskeletal Mg was also observed in Pb-treated crabs. There was a significant increase in Pb content found in the gills, hepatopancreas, muscle, and hemolymph in Pb-treated crabs. The rank of the Pb level among three soft tissues in a decreasing order is hepatopancreas > gill > muscle. This is the first study to present evidence that Pb disrupts postecdysial exoskeletal calcification in a crustacean. Environ Toxicol Chem 2022;41:474-482. © 2021 SETAC.

The electronic structure, charge transport, and excitonic properties of organic molecules critically govern their performance in organic light-emitting diodes (OLEDs). Here, we report a systematic density functional theory (DFT) study of 55 derivatives of 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), functionalized by attaching eleven electron-donating and electron-withdrawing substituents at five distinct positions. Fundamental parameters including bandgap, ionization potential, electron affinity, quantum chemical reactivity descriptors, optical absorption, and exciton binding energies (EBEs) were rigorously evaluated. This work demonstrates that substituent identity and attachment position significantly influence molecular optoelectronic characteristics. Notably, benzo[c][1,2,5]thiadiazole substitution at the carbazole site provided an optimal bandgap (2.99 eV), low EBE (0.38 eV), and visible-range absorption (∼476 nm), ideal for emissive-layer applications. TCNQ attached at the biphenyl core exhibited the smallest bandgap (0.856 eV), highest electron affinity (4.86 eV), and maximum softness, highlighting excellent electron-transporting capabilities. Furthermore, 1,4-dicyanobenzene substitution at the biphenyl position combined balanced reactivity with electronic stability, suitable as a phosphorescent OLED host. Corroborated by Density of States profiles, molecular electrostatic potentials, and UV-Vis spectra, this work provides valuable design principles for developing next-generation high-performance OLED materials. • Systematic DFT study of 55 CBP derivatives modified by diverse electron-donating and electron-withdrawing substituents. • Identification of optimal derivatives tailored for emissive, electron transport, and host roles in OLED devices. • Benzo\[c]\[1,2,5]thiadiazole at carbazole sites exhibits ideal electronic structure for emissive layers. • TCNQ substitution at the biphenyl core enhances electron affinity and transport capability. • 1,4-Dicyanobenzene substitution at biphenyl position optimizes electronic stability for phosphorescent OLED host applications.

Ternary spinel oxides are promising materials due to their potentially versatile properties resulting from the disorder inherent in their crystal structure. To fully unlock the potential of these materials, a deeper understanding of their electronic structures, both as pristine and defective crystals, is required. In the present work, we investigate the effects of oxygen vacancies on the electronic structure and charge transport properties of the ternary spinel oxide Mn x Fe3-x O4, modeled on epitaxial thin films of the material, using density functional theory + U (DFT + U). The formation energy of a single oxygen vacancy in the spinel cell is found to be large and unaffected by changes in stoichiometry, in agreement with experimental results. We find that the immediate vicinity of the vacancy has a marked impact on the formation energy. In particular, Mn cations are found to be preferred over Fe as sites for charge localization around the vacancy. Finally, we examine the charge transport in the defective cell using the formalism of Marcus theory and find that the activation barrier for electron small-polaron hopping between sites not adjacent to the vacancy is significantly increased, with a large driving force toward sites that reside on the same (001) plane as the vacancy. Hence, vacancies delay charge transport by increasing the activation barrier, attributed to a rearrangement of vacancy-released charge on the cations immediately neighboring the vacancy site. These results highlight the impact of oxygen vacancies on charge transport in spinel oxides.

First principle study on interfacial interaction of black phosphorus and CsBr vdW heterostructure

THe memristor is a key memory element for neuromorphic electronics and new generation flash memories. One of the most promising materials for memristor technology is silicon oxide SiO x , which is compatible with silicon-based technology. In this paper, the electronic structure and charge transport mechanism in a forming-free SiO x -based memristor fabricated with the plasma enhanced chemical vapor deposition method is investigated. The experimental current-voltage characteristics measured at different temperatures in high-resistance, low-resistance and intermediate states are compared with various charge transport theories. The charge transport in all states is limited by the space charge-limited current model. The trap parameters, responsible for the charge transport in a SiO x -based memristor in different states, are determined.

Molecular wires represent a cornerstone of next-generation nanoelectronics, yet the design of highly efficient, short molecular conductors remains a significant challenge. In this study, we present a catalyst-free, green synthetic route for the preparation of anilino-1,4-naphthoquinone enaminone derivatives via aqueous-phase Michael addition between anilines and 1,2-naphthoquinone-4-sulfonic acid sodium salt. The reaction proceeds rapidly at room temperature, yielding products with excellent efficiency (96–98%) and exceptional purity, as confirmed by comprehensive spectroscopic characterization (FT-IR, UV-Vis, 1H and 13C NMR, MS) and elemental analysis. Single-crystal X-ray diffraction further validated the molecular structures of representative compounds. Theoretical investigations using Density Functional Theory (DFT) and Quantum Theory of Atoms in Molecules (QTAIM) provided deep insights into the electronic properties and charge transport behavior of these systems. Key analyses included cohesive energy calculations, UV-Vis exciton energy profiles, frontier molecular orbital energies (HOMO/LUMO), chemical reactivity descriptors (hardness, softness, chemical potential), and dipole moment variations under external electric fields (0-140 × 10− 4 a.u.). Additionally, localized orbital locator (LOL) contours, electron density Laplacians, and current-voltage (I–V) characteristics based on Landauer theory were evaluated to assess charge transport efficiency. Comparative analysis reveals that extending the π-conjugation in a molecular system markedly improves its electronic properties, leading to lower energy gaps, enhanced conductance, and greater field responsiveness, which are critical for molecular wire functionality. Furthermore, this work combines sustainable synthesis with advanced computational modeling to offer a robust framework for the design and evaluation of short molecular wires for nanoelectronic devices.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-22175-z.