Monolayer Of Molecules Research Articles

Surface Modification of Liquid Metal with p-Aniline Derivatives toward Bioapplications: Biosensing as an Example.

It is a long-lasting research topic to avoid the formation of oxidation layers on gallium-based liquid metals. This study has developed a simple general method for modification of the eutectic gallium-indium (EGaIn) surface with p-aniline derivatives to introduce a monolayer of organic molecules with versatile functional groups. The binding affinity of carboxylic acid groups, amine groups, or thiol groups with EGaIn is in the order SH > NH2 > COOH. For the first time, it is evidenced that both NH2 and SH groups can coexist on the EGaIn nanoparticle surface with the binding affinities of 30 and 70%, respectively. The formation of these organic molecules on the EGaIn surface antioxidizes and thus stabilizes the EGaIn nanoparticles, while increasing the conductivity of EGaIn significantly. The resulting EGaIn nanoparticles have very good distribution in both ethanol and aqueous solutions and rich surface chemistry, making them suitable for the following attachment of biomolecules such as aptamers, antibodies, or enzymes for biomedical applications. As an example, the EGaIn surface is successfully modified with p-aminobenzoic acid followed by the attachment of an insulin aptamer, which can be used for the electrochemical detection of insulin with the lowest detectable concentration limit of 1 pM. This study reveals the modification of EGaIn nanoparticles with p-aniline derivatives with versatile functional groups to antioxidize EGaIn in a biological environment, opening a door for gallium-based liquid metals toward biomedical applications.

Self‐Assembled Amphiphilic Monolayer for Efficient and Stable Wide‐Bandgap Perovskite Solar Cells

AbstractThe applications of wide‐bandgap (WBG) perovskite solar cells (PSCs) are limited by their subpar efficiency and stability due to their high density of defects, especially those at interfaces. Theoretical analyses suggest a monolayer of molecules, which is of minimum thickness and, hence, minimum resistance across the interface, possessing multifunctional groups and a permanent dipole, should effectively passivate the defects and minimize energy losses at interfaces. Herein, a self‐assembled monolayer (SAM) composed of amphiphilic molecules is designed and assembled as the interface layer to reduce the energy loss and enhance interface coupling between the perovskite and hole transport layer. It is found that the SAM also builds a back surface field through a p‐type doping effect, which promotes hole extraction and suppress the carrier recombination. Consequently, a remarkable power conversion efficiency (PCE) of 20.4% in parallel with a high open‐circuit voltage up to 1.25 V is attained. Additionally, an indoor PCE of 38.7% is realized. Both are among the best in their respective categories. Moreover, an all‐perovskite tandem solar cell is configured, presenting a decent PCE of 23.2%. This work emphasizes the significance of WBG PSCs for optoelectronic applications and indicates the eminent effects of SAMs for optimization of WBG PSCs.

Early warning of Diaporthe infection in kiwifruit soft rot by plasmonic dimer-enhanced Raman spectroscopy.

Diaporthe genus is the dominant pathogens of kiwifruit soft rot with long incubation period and rapid onset and very hard to detect in advance. It is of great significance to develop point-of-care tests for disease prevention and field management. Here we screen a pair of genus-level primers for constructing plasmonic dimer Rayleigh/Raman spectroscopy, which enables rapid, specific, and sensitive detection of Diaporthe genus in real kiwifruits. Dark-filed Rayleigh scattering clearly visualizes the target-induced dimer assembly of nanoprobes. Plasmonic dimer-enhanced Raman spectroscopy has high specificity for 12 common isolates of Diaporthe genus in one batch samples with highly accurate results and much higher sensitivity than polymerase chain reaction (PCR). It realizes the recognition of Diaporthe infection at an early stage of 24h when the kiwifruits do not have any noticeable symptoms. It demonstrates a bright prospect of point-of-care tests for early warning of kiwifruit soft rot infection and quality control.

Condensation of capillary water and decreased surface energy cause increased soil water repellency in sandy soil

AbstractPredicting soil water availability to crops in water‐repellent sandy soil is complicated as soil water repellency (SWR) responds non‐linearly to soil water content. Others have hypothesised that the development of a monolayer of water molecules results in SWR increasing before SWR declines with a further increase in soil water content. In a previous study, we found that SWR increases when above 0.28–0.86% threshold soil water content. Thus, our objective was to determine the underlying mechanisms responsible for why SWR increases when above a certain threshold soil water content in a sandy soil. A water adsorption isotherm was constructed by exposing a water‐repellent sandy soil to increasing relative humidity (dynamic vapour sorption technique) to evaluate if the development of a monolayer of water molecules was responsible for the increased SWR response. The increased SWR when above 0.66% threshold soil water content was found to coincide with the capillary condensation of water in the soil. The inverse gas chromatography technique was used for the first time in soil particles' surface energy analysis to investigate why SWR increases when above the threshold soil water content by determining the total, dispersive (non‐polar), and specific surface (polar) energy of the soil at two relative humidities (0% and 90%). Wettable sandy soil (98% soil organic carbon removed) was included as a control to further assess if soil organic carbon in the water‐repellent soil influences the surface energy of the soil. The mean of total, dispersive, and specific surface energy decreased for both wettable and water‐repellent sandy soils when exposed to 90% relative humidity, suggesting that there was limited effect of soil carbon on the increased SWR when above the threshold soil water content since most organic carbon was removed from the wettable soil. We also investigated if there is any difference in the surface energy heterogeneity when exposed to 90% relative humidity to gain insight into surface chemistry heterogeneity of the soil particles' surfaces. Exposing soils to 90% relative humidity decreased the heterogeneity of the total and dispersive surface energy of both wettable and water‐repellent sandy soil indicating a more uniform surface chemistry than when exposed to 0% relative humidity.Highlights Examined why soil water repellency (SWR) in a sandy soil increases at low soil water content. Explored underlying mechanisms via water adsorption isotherm and surface energy of a sandy soil. Increased SWR coincided with capillary water condensation and is likely due to counterion effects. Quantitative data presented new mechanisms on why SWR increases with increasing soil water content.

Study ofn-Alkanethiol Self-Assembly Behavior on Iron Particles: Effect of Alkyl Chain Length and Adsorption Solvent on Resulting Iron-Based Magnetorheological Fluids

Self-assembled monolayers (SAMs) of organic molecules on metal surfaces are a type of inexpensive surface coating often used to improve metal substrate properties for sensors, electrochemistry, and nanofabrication applications. Iron, specifically, is one of the most commonly used metals, both as a pure metal and as an alloy due to its high conductivity, strong ferromagnetism, and low cost. However, magnetorheological fluids, which have shown impressive energy dampening in fields from civil infrastructure to biomedical devices utilizing iron dispersions, have suffered from low reliability and efficiency due to iron particle oxidation, corrosion, and settling. To understand the effect of self-assembled monolayers on iron and both the adsorbed particle's resistance against aggregation and performance impact, this work performs an in-depth study on alkanethiol-based self-assembled monolayers on iron particles. Adsorption of alkanethiols and the generation of SAMs on micron-sized iron particles were evaluated as a function of adsorption solvent polarity and alkanethiol chain length. Maximum alkanethiol loading, determined from appropriate isotherms, was found to strongly be a function of both parameters. Alkanethiol adsorption increased with increasing alkyl chain length and increasing solvent log P values in polar solvents. With respect to magnetorheologically relevant parameters, alkanethiol adsorption did not show any significant effect on both the magnetic properties of iron (as particles) and fluid on-state yield stress. The colloidal stability of n-alkanethiol adsorbed iron-based magnetorheological fluids (MRFs) was a function of both n-alkanethiol chain length and the iron particle adsorption solvent. MRFs composed of hexadecanethiol adsorbed iron prepared in polar solvents like methanol and ethanol showed excellent sedimentation stability compared to all other MRFs prepared in this study.

Wafer-Scale Full-Coverage Self-Limiting Assembly of Particles on Flexible Substrates.

Self-limiting assembly of particles represents the state-of-the-art controllability in nanomanufacturing processes where the assembly stops at a designated stage, providing a desirable platform for applications requiring delicate thickness control such as optics, electronics, and catalytic systems. Most successes in self-limiting assembly are limited to self-assembled monolayers (SAMs) of small molecules on inorganic, chemically homogeneous rigid substrates (e.g., Au and SiO2) through surface-interaction mechanisms. Similar mechanisms, however, cannot achieve a uniform assembly of particles on flexible polymer substrates. The complex configurations and conformations of polymer chains create a surface with nonuniform distributions of chemical groups and phases. In addition, most assembly mechanisms require good solvent wettability, where many desirable but hard-to-wet particles and polymer substrates are excluded. Here, we demonstrate a collision-based self-limiting assembly (CSA) to achieve wafer-scale, full-coverage, close-packed monolayers of hydrophobic particles on hydrophobic polymer substrates in aqueous solutions. The kinetic assembly and self-limiting processes are facilitated and controlled by the combined acoustic and shear fields. We envision many applications in functional coatings and showcase their feasibility in structural coloration. Importantly, such functional coatings can be repaired using CSA, and both particles and polymer substrate can be recycled.

Adsorption of atomic and molecular monolayers on Pt-supported graphene

Adsorption energies of monolayers of noble gases (Ar, Kr, Xe) and small molecules (N2, O2, CO, CH4, C2H6, and C3H8) on graphene supported by Pt(111) surface were computed by DFT, corrected for temperature and zero-point effects, and, compared to the recent temperature-programmed desorption experiments (Smith et al., 2016). The results indicate that some of the considered DFT exchange–correlation functionals reasonably well describe molecule–graphene/Pt(111) noncovalent interactions. For selected models, fixed-node diffusion Monte Carlo computations were used for ultimate cross-validation of interaction energies between the molecule and free-standing graphene.

Strain-engineered S-HfSe2 monolayer as a promising gas sensor for detecting NH3: A first-principles study

The development of high-performance gas sensing materials is one of the development trends of new gas sensor technology. In this work, in order to predict the gas-sensitive characteristics of HfSe2 and its potential as a gas-sensitive material, the interactions of nonmetallic element (O, S, Te) doped HfSe2 monolayer and small molecules (NH3 and O3) have been studied by first-principles based on density functional theory. The results show that the adsorption of NH3 and O3 on pristine HfSe2 monolayer is weak, and the adsorption strength can be significantly improved by doping O. And O-HfSe2 is chemical adsorption to O3 with large adsorption energy and transfer charge, and the band gap of OHfSe2 disappears after adsorbing O3, indicating that the adsorption of O3 has a significant effect on the electrical properties of the substrate. These mean that O3 is difficult to recover from the substrate surface, thus preventing O-HfSe2 from developing into a sensitive material for O3 detection. After doping S, the charge transfers and adsorption strength to NH3 are the largest, but it is still small. So, the strain effect on the S-HfSe2/NH3 adsorption system is also studied. The results indicate that the adsorption strength of S-HfSe2 to NH3 can be enhanced by stretching S-HfSe2 along x-axis. After absorbing NH3, the conductivity of x-axis strained S-HfSe2 changes, which suggest its sensitivity. And the predicted recovery times of S-HfSe2 surfaces with εx=4%, 6% and 8% are 0.027 s, 1.153 s and 102.467 s, respectively, which suggests that the S-HfSe2 monolayer has the potential to be developed as a sensitive material for NH3 detection. These adsorption mechanism studies can also serve as a theoretical foundation for the experimental design of gas-sensing materials.

Activity of AC electrokinetically immobilized horseradish peroxidase.

Dielectrophoresis (DEP) is an AC electrokinetic effect mainly used to manipulate cells. Smaller particles, like virions, antibodies, enzymes, and even dye molecules can be immobilized by DEP as well. In principle, it was shown that enzymes are active after immobilization by DEP, but no quantification of the retained activity was reported so far. In this study, the activity of the enzyme horseradish peroxidase (HRP) is quantified after immobilization by DEP. For this, HRP is immobilized on regular arrays of titanium nitride ring electrodes of 500nm diameter and 20nm widths. The activity of HRP on the electrode chip is measured with a limit of detection of 60fg HRP by observing the enzymatic turnover of Amplex Red and H2 O2 to fluorescent resorufin by fluorescence microscopy. The initial activity of the permanently immobilized HRP equals up to 45% of the activity that can be expected for an ideal monolayer of HRP molecules on all electrodes of the array. Localization of the immobilizate on the electrodes is accomplished by staining with the fluorescent product of the enzyme reaction. The high residual activity of enzymes after AC field induced immobilization shows the method's suitability for biosensing and research applications.

Effect of chitosan on the interactions between phospholipid DOPC, cyclosporine A and lauryl gallate in the Langmuir monolayers

The Langmuir technique allows for the characterization of monolayers of biological and/or biologically active compounds which have high potential for application in tissue engineering to improve the implants biocompatibility. This group of substances includes 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), cyclosporine A (CsA), lauryl gallate (LG), and chitosan (Ch). The single (DOPC, CsA, LG), binary (DOPC-CsA 1:1) and ternary (DOPC-CsA-LG 3:3:2, 1:1:2, 1:1:6 that correspond to χLG = 0.25, 0.50, 0.75) monolayers on the acidic subphase with or without chitosan (Ch) were characterized using the Langmuir technique coupled with the surface potential meter. The dependence of the surface pressure and the surface potential on the area per molecule (π−A and ∆V−A isotherms, respectively) was determined. Based on the above isotherms data, the compression modulus (Cs−1), excess and total Gibbs energy of mixing (∆Gexc and ∆Gmix) as well as the apparent dipole moment (μa) were calculated. These parameters allowed drawing conclusions about the molecular packing, the orientation of molecules, the type and magnitude of interactions within the monolayers, and finally about their stability, depending on the components proportions and the contribution of Ch molecules. The main findings indicated that the insertion of LG to the binary DOPC-CsA 0.50 monolayer resulted in a shift of the π−A isotherms towards smaller areas per molecule, the smaller areas the higher amount of LG. That correlated with an increase in packing density (larger Cs−1 values) and an attraction between the molecules (revealed by the negative ∆Gexc and ∆Gmix values) in the three-component monolayers. Furthermore, the addition of chitosan (Ch) molecules into the subphase stiffened the multicomponent (DOPC-CsA or DOPC-CsA-LG) films. The strengthening of the attractive interactions and better miscibility were observed for all the DOPC-CsA-LG films. Therefore, these monolayers spread on the Ch subphase were found to be thermodynamically stable (among them the most stable was DOPC-CsA-LG 0.50) and could be successfully used for coating implants in order to improve their biocompatibility with the surrounding tissues.

Accurate Determination of Adsorption-Energy Differences of Metalloporphyrins on Rutile TiO2(110) 1 × 1.

Understanding the adsorption of organic molecules on surfaces is of essential importance for many applications. Adsorption energies are typically measured using temperature-programmed desorption. However, for large organic molecules, often only desorption of the multilayers is possible, while the bottom monolayer in direct contact to the surface cannot be desorbed without decomposition. Nevertheless, the adsorption energies of these directly adsorbed molecules are the ones of the most interest. We use a layer-exchange process investigated with X-ray photoelectron spectroscopy to compare the relative adsorption energies of several metalated tetraphenylporphyrins on rutile TiO2(110) 1 × 1. We deposit a mixture of two different molecules, one on top of the other, and slowly anneal above their multilayer desorption temperature. During the slow heating, the molecules begin to diffuse between the layers and the molecules with the stronger interaction with the surface displace the weaker-interacting molecules from the surface and push them into the multilayer. The multilayers eventually desorb, leaving behind a monolayer of strongly interacting molecules. From the ratio of the two different porphyrin molecules in the residual monolayer and the desorbed multilayer, we can calculate the equilibrium constant of the layer-exchange process and thereby the difference in adsorption energy between the two different porphyrin molecules.

Effect of edge groups on the electronic transport properties of tetrapodal diazatriptycene molecule

We conduct ballistic transport calculations to study the electronic transport properties of diazatriptycene molecule which can be self-assembled on metallic surfaces with uniform coverage and upright orientation of the functional head group. Due to its structural asymmetry, the molecule shows a clear current rectification , where the level of the rectification depends on the nature of the head group. For example, current rectification can be increased by more than a factor of 2 by anchoring the molecules to the electrode by CN functional group or introducing insulating CH 2 group between the thiol end group and the adjacent phenyl ring. Our findings show the possibility of creating self-assembled monolayer of DAT molecules with controlled electronic transport properties through functionalization of the head group. • Electronic transport in diazatriptycene molecule is studied using DFT. • The molecule shows current rectification due to structural asymmetry. • The rectification level depends on the nature of the head group. • Electronic transport can be controlled by changing the anchoring groups.

Antifreezing Hydroxyl Monolayer of Small Molecules on a Nanogold Surface.

The rational design of ice recrystallization inhibition (IRI) materials is challenging due to the poor understanding of the IRI mechanism at the molecular level. Here we report several new findings about IRI. (1) A dense hydroxyl monolayer of small molecules, e.g. 6-aza-2-thiothymine (ATT), adsorbed on a nanogold surface was demonstrated, for the first time, to have IRI activity. Five structural analogues adsorbed on groups nanogold with outward hydroxyl or methyl were created to evidence the origin of IRI activity. (2) Their IRI mechanism is closely related to the density of hydroxyls on a nanogold surface. However, the hydrophobic interaction in our model is not essential for macroscopic IRI activity. (3) A molecular dynamics simulation elucidates the hydroxyl density dependent IRI trajectories underlying the experimental observations, and the radial distribution function reveals that the methyl even slightly hinders the formation of hydrogen bonding due to a hydrophobic interaction. This work sheds more light on the IRI mechanism that should help in the customization of novel IRI materials.

The aggregation of 1,3,4-thiadiazole based Hockey stick shaped Mesogen in Langmuir-Blodgett thin film in comparison to that of 1,3,4-oxadiazole

Bent Core Mesogens are remarkably interesting achiral Liquid Crystals. These grab attention for their utility. The compound, taken for investigation, is a Schiff base addition product, composed of 2-(4β-aminophenyl)-5-(4?β-butyloxyphenyl)-1,3,4- thiadiazole and 4-n-hexadecyloxy salicylaldehyde. The property of this imine derivative is in accordance with liquid crystal and is a Bent Core Mesogen (BCM). The thin layers were prepared with the help of Langmuir-Blodgett apparatus. The morphology and photo-physical characteristics of thin films were examined in comparison to similar BCM derivative of 1,3,4-Oxadiazole. The expectation was the formation of monolayer of molecules on the substrate. Practically there were layer of clusters on the substrate. Both molecules form nano clusters. The typically different aggregates by the thiadiazole moiety in comparison to oxadiazole moiety are revealed. Cluster formation is also supported by the Atomic Force Microscopic (AFM) images.

On the Role of Collective Electrostatic Effects in Electronic Level Pinning and Work Function Changes by Molecular Adlayers: The Case of Partially Fluorinated DNTTs Adsorbed Flat‐Lying on Various Metals and Hetero‐Structures

AbstractModifying the work function of metal electrodes by monolayers of molecules with specifically tailored electronic properties is a versatile tool, but such chemical modifications often also affect the adsorption geometry and packing density, making microscopic modeling difficult. Using scanning tunneling microscopy, it is shown that the recently synthesized partially fluorinated dinaphthothienothiophenes (DNTTs) adopt the same interface structure on different metal substrates independent of the degree of fluorination. Combining Kelvin probe measurements and density functional theory (DFT) calculations, a highest occupied molecular orbital (HOMO) pinning effect for such FxDNTTs on Au(111) and Ag(111) induced by collective electrostatic interactions in the monolayer is observed. Since the adsorption of weakly interacting molecules such as the FxDNTTs is not restricted to specific surfaces as is the case with SAMs, this concept is extended to metal substrates with quite different work function values. For a low work function surface such as Cs(110), a lowest unoccupied molecular orbital (LUMO) pinning effect is predicted at the theoretical level. Since such alkali metal surfaces are not experimentally accessible, a well‐defined Cs monolayer on Cu(100) as a low work function substrate is used instead. For this substrate, however, a variation is observed in the LUMO energies and the work function as a function of the degree of fluorination. This is attributed to the formation of a second interface dipole at the buried Cs/Cu interface, which is modulated with the degree of fluorination and competes with the dipole at the outer molecule/Cs interface. Such a second internal interface dipole, which can be modified by the top layer, has to be considered when going to more complex heterointerfaces.

Hydrogen adsorption and storage behaviors of Li-decorated PdS2 monolayer: An extended tight-binding study based on DFT

The hydrogen adsorption and storage of the lithium-decorated PdS2 monolayer at nano-size has been investigated by using extended tight-binding (GFN1-xTB) based on density functional theory (DFT). The calculation results demonstrate that the average adsorption energies of 1–5H2 change in 0.47–0.20 eV/H2 range which decreases with increasing of adsorbed hydrogen molecule number. The gravimetric density for hydrogen storage adsorption with 12Li atom and 60H2 molecules of Li-decorated PdS2 monolayer is about 6.98 wt% considered as possible application in hydrogen storage. The examination of the hydrogen store mechanism between the monolayer and hydrogen molecules is presented by polarization between Pd and H2, which can be effect on the adsorption behavior.

Eliminating Leakage Current in Thin‐Film Transistor of Solution‐Processed Organic Material Stack for Large‐Scale Low‐Power Integration

AbstractFor organic thin‐film transistors (OTFTs) made of solution processed stacks of organic semiconductor and dielectric materials, it is a grand challenge to eliminate the leakage current paths. With a top‐gate bottom‐contact structure, this work introduces a strong dipole interfacial layer made of self‐assembled monolayer (SAM) molecules at metal‐semiconductor contacts to suppress minority carrier injection for low leakage and stable operation, while not affecting majority carrier injection. Both gate insulator (GI) leakage and parasitic leakage in the device architecture are also effectively suppressed with a sputtering‐resistant polymer GI layer and photolith patterned OSC islands, respectively. The devices present a decent mobility with a typical value of 1.98 cm2 V–1 s–1, record‐low leakage current at 10–18 A µm−1 and large ON/OFF ratio (>1010) in a wide gate voltage range (100 V), reaching the theoretical limit and also the best level of inorganic counterparts despite much lower processing temperature (120 °C). Manufacturability of the material stack is verified on a 200 mm × 200 mm substrate and the fabricated 4.7 in. active‐matrix organic light‐emitting diode display, integrating more than 150 000 OTFTs, can be operated at ultra‐low frame‐rate (0.1 Hz) for power saving.

A universal concept for area‐selective assembly of metal oxide core‐shell nanoparticles, nanorods, and organic molecules via amide coupling reactions

AbstractThe deposition of nanomaterials (NMs) on substrate is a pertinent for a variety of applications in nanometer‐sized electronics, mechanics, or catalysis. This paper establishes a universal and simple approach for assembly of functionalized metal oxide core nanoparticles (NPs) and nanorods (NRs) on a substrate with uniformity, area‐selectivity, and full order control. Particularly, the aluminium oxide (AlOx) NPs, titanium dioxide (TiO2) NRs, and TiO2 NPs functionalized by self‐assembled monolayer (SAM) molecules are deposited on substrate alternatively layer‐by‐layer. This assembling is performed in solution on the pre‐patterned surface with SAM molecules via amide coupling reactions in order to achieve the reaction‐orthogonality. Moreover, this stacking of inorganic NPs/NRs in a terminated implementation is progressed into latter layer of TiO2 NPs functionalized by 1‐aminopyrene molecules representing an example of hybrid organic‐inorganic formation with fluorescence emission. The deposited layers are characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and total internal reflection fluorescence microscope (TIRFM). The significant versatility of stacked metal oxide core‐shell NPs/NRs via based‐solution method represents excellent and efficient applicability in manufacture of hybrid organic–inorganic nanostructure.

Oriented adsorption of NO2 on WSe2 monolayer

An oriented adsorption behavior of NO2 is disclosed on the WSe2 monolayer in this work regardless the monolayer is perfect or defective based on density functional theory study by large-scale sampling. The presence of typical defects, including selenium vacancy, tungsten vacancy, and antisite defect of selenium on tungsten site, does not modify the anisotropic adsorption behavior of NO2 molecule at all. The adsorbed NO2 exhibits similar behavior on the four kinds of monolayers with its extending orientation all main lines along the two directions of the Se–W bond and the Se–W–Se trough, in spite of the symmetry is decreased somewhat from trigonal of the perfect monolayer to bilateral of the defective monolayers. Molecular dynamic simulations well reproduce these trends. The anisotropic adsorption behavior can be attributed to the polar properties of both heteroatomic bond of the WSe2 monolayer and NO2 molecule itself. Out of plane polarization is believed to play key role in the vertical and then the oriented adsorption behavior formation. The sensitivity is estimated to be very good based on moderate adsorption energy (0.35, 0.42, 0. 95 and 0.78 eV on pure, selenium vacancy, tungsten vacancy, and selenium on tungsten site monolayers) and considerable charge transfer number (0.205, 0.208, 0.164, and 0.160 e, respectively), with different degrees of change by defect. These fantastic findings may provide substantial foundation for wide applications beyond thought.

Doping of two thallium atoms in silicene nanoribbons in the electric field

Abstract The low-dimensional material that revolutionizes technology, silicene is a monolayer of silicon molecules, which is a potential material. Silicene nanoribbons (SNRs) are one-system silicene ribbons with two hydrogen-modified edges. Two thallium atoms will be doped in each unit cell of the SNRs, the electric field acting on the doped system has a magnitude of 0.1V/angstrom. The configurations studied here all exhibit stability because of the bonds between atoms. The configurations studied here all exhibit stability because of the bonds between atoms. Density functional theory (DFT) and VASP software are used to study and simulate materials.