Semiconductive Materials Research Articles

Anomalous narrow-band optical anisotropy of MoO2 crystal in the visible regime

The emergence of anisotropic two-dimensional (2D) materials provides a platform for the cutting-edge nano- and optoelectronic devices. Exploring low-dimensional materials and revealing their anisotropic behavior are crucial for designing angle-dependent nanodevices. The metallicity of molybdenum dioxide (MoO2) crystal differentiates it from the most commonly studied semi-conductive anisotropic 2D materials. However, the studies on its optical anisotropy are still lacking. Here, two most commonly obtained shapes of rhombic and hexagonal MoO2 were synthesized by one step method of chemical vapor deposition. The rhombic and hexagonal MoO2 display a slight frequency shift of 1–5 cm−1 depending on the variation modes, but the Raman modes at 366 cm−1 remain unaltered. Using a combination of differential reflectance spectroscopy and reflectance difference spectroscopy, we revealed the unusual narrow-band optical anisotropies of rhombic and hexagonal MoO2 crystals in the visible wavelength region due to its unique metallic properties. Furthermore, it is found that the center wavelengths of the narrow-band optical anisotropy of the MoO2 crystal can be effectively adjusted by coherent optical interference. Our results present an interesting anisotropic metallic 2D candidate and an effective cavity-based approach to regulate the center wavelengths of as-obtained narrow-band optical anisotropy, which is highly beneficial for the wavelength-selected devices.

One-touch calibration of hum-noise-based touch sensor for unknown users utilizing models trained by different users

Hum-noise-based touch sensors (HumTouch) are capable of recognizing human touch on semiconductive materials using the current leaking from the finger to the surface. Thus far, calibration for these hum-noise-based touch sensors has been performed for individual users because of the individual differences in hum-driven electric currents in human bodies. However, for applications designed for unknown users, time-consuming calibration for individual users is not preferred, and a new user should be able to use the sensor immediately. For this purpose, we propose a new calibration method for HumTouch. In this method, learning datasets collected from multiple people and a few extra samples from a new user are collectively used to establish a touch localization estimator. The estimator is computed using the kernel regression method with weighted samples from the new user. For a 20 times 18 cm^2 paper, the mean localization error is reduced from 1.24 cm to 0.90 cm with only one sample from the new user. Hence, a new user can establish a semipersonalized localization estimator by touching only one point on the surface. This method improves the localization performance of HumTouch sensors in an easy-to-access manner.

Synergistic effects of doping, composite formation, and nanotechnology to enhance the photocatalytic activities of semiconductive materials

Graphene, the promising carbon allotrope, has recently gained substantial research attention due to its unique physiochemical properties and distinctive 2D structure. Graphene-based composites have remarkable electronic and crystal properties and have emerged as promising photocatalysts owing to their greater surface area, superior adsorption, and charge transfer capacity. In this study, we made indium-doped molybdenum trioxide (In–MoO3) nanobelts. We combined them with nanosheets of reduced graphene oxide (rGO) to create a new photocatalyst for removing organic compounds (textile colors) from industrial waste. The prepared materials' surface morphology, crystalline structure, functional group detection, light absorption capacity, and electrochemical behavior have been investigated and validated using well-established characterization techniques. We examined the photocatalytic activity of freshly produced catalysts under the same circumstances by mineralizing the MB dye. The rGO/In–MoO3 composite outperformed pure MoO3 and In–MoO3 samples in photo-mineralization activity. After being exposed to light for one hundred minutes, the rGO/In–MoO3, In–MoO3, and MoO3 photocatalysts removed approximately 96%, 64%, and 49% of the MB dye, respectively. According to the reaction kinetics, the rGO-supported In–MoO3 sample removed the dye at a rate of 0.0250/min. This rate was 2.43 and 4.03 times higher than the rate that was attained by the samples that consisted just of bare MoO3 and In–MoO3, respectively. In chronoamperometric analysis, the rGO/In–MoO3 catalyst showed a 4.68 and 1.65-fold higher transient photocurrent response than the MoO3 and In–MoO3 catalysts, respectively. The synergistic properties of the significantly conducting graphene matrix and nanoscaled In–MoO3 were primarily responsible for the rGO/In–MoO3's improved photomineralization performance. These effects increased the separation of e−-h+ and improved the light-harvesting capacity. This new research shows a practical way to make highly effective photocatalysts that can be used in wastewater treatment in industry.

Selective NO2 Detection by Black Phosphorus Gas Sensor Prepared via Aqueous Route for Ship Pollutant Monitoring

The emission of nitrogen dioxide (NO2) caused by marine transportation has attracted worldwide environmental concerns. Two-dimensional (2D) black phosphorus (BP) is an emerging semiconductive material with the advantages of high electron mobility, a layer-dependent direct band gap and a large specific surface area. These properties ensure excellent potential in gas-sensing applications. In this work, BP quantum dots (QDs) are synthesized from commercial red phosphorus (RP) fine powder via the aqueous route. The BP QDs show uniform size distribution with an average size of 2.2 nm. They are employed to fabricate thin film gas sensors by aerial-assisted chemical vapor deposition. The microstructure, morphology and chemical composition are determined by various characterizations. The sensor performances are evaluated with the optimized response set to 100 ppm NO2 of 10.19 and a sensitivity of 0.48 is obtained. The gas sensor also demonstrates excellent repeatability, selectivity and stability. The fabricated thin film gas sensor assembled by BP QDs exhibits prospective applications in selective NO2 detection for marine gaseous pollutant monitoring and control.

Effects of PCBM loading on high sensitive P3HT based vertical bulk resistive X-ray detector

Recently, semiconductive polymeric materials have attracted attention as an active layer for detecting ionizing radiation because of their excellent properties such as flexibility, easy production, solution processability and low-cost production. This paper presents X-ray detection properties of Poly(3-hexylthiophene) (P3HT):Phenyl C61 butyric acid methyl ester (PCBM) blend structure with different PCBM loading ratios. P3HT:PCBM mixing ratio was changed from 1:0 to 1:2. Top contact of the pure and blend structured device were produced by using a solution based graphite ink. Devices were constructed with vertical bulk resistive architecture within an ohmic electrode structure as ITO/PEDOT:PSS/P3HT:PCBM/Graphite configuration. Graphite electrode was coated on the active layer with the spray coating method. All devices exhibited ohmic current-voltage (I–V) characteristics. The blend structured devices exhibited stable saw-tooth type behaviour in photocurrent responses against the on and off states of X-rays. Saw-tooth type responses could be evaluated as major evidence for a potential usage of organic electronic device technology direct radiation detectors. Although the best sensitivity value to X-ray was obtained with the blend structure with equal ratio, it was observed that the rise and decay times were shortened with the increase in the amount of PCBM in the blend structure from. • P3HT:PCBM active layer based X Ray detectors were fabricated and effect of PCBM ratio was investigated. • Spray coated graphite electrode was used as the top ohmic contact for all devices. • P3HT:PCBM ratio was changed as (1:0), (1:0.5), (1:1), (1:2) and investigate PCBM concentrations how effect X Ray detection parameters with different X Ray dose rates under 10 V bias. • Best sensitivity value to X-ray was obtained with the blend structure with equal ratio of PCBM and P3HT (1:1).

Charge Carrier Injection Characteristics of Semiconductive and Metal Electrodes in XLPE

In this article, a method using a barrier layer to realize electrode unipolar charge carrier injection is proposed to study the injection characteristics of positive and negative charge carriers by different electrode materials. The space charge distribution in XLPE/polytetrafluoroethylene (PTFE) was measured by the pulsed electroacoustic (PEA) method, and the relationship between the accumulation rate of injected charge carriers and electric field strength at the electrode interface was further established. It was found that the aluminum (Al) electrode had a greater charge injection capability than the semiconductive layer, while both were stronger than that of the gold (Au) electrode. The combined analysis of space charge measurement results and theoretical model verified the accuracy of the relationship between the accumulation rate of injected charge carriers and electrode field to characterize charge injection behavior. Space charge measurement in single-layer XLPE samples verified its validation. This study provides techniques and theoretical guidance for the testing and development of semiconductive materials in XLPE direct-current (dc) cables.

Electrodeposition and Characterization of Poly 3-Amino-1,2,4-Triazole-5-Thiol Films on Brass Electrode in 0.1 M Methanol

The electrochemical synthesis of conductive polymers (CPs) or semiconductors (SCs) is influenced by several parameters, such as the choice of monomers, solvents, support electrolytes, and the nature of dopants, which induce electrical conductivity in conjugated organic polymers. This work describes the electropolymerization of 3-amino-1,2,4-triazole-5-thiol (ATT) on a 60Cu-40Zn brass alloy. The synthesis of polymer film by electrochemical method was carried out by cyclic voltammetry and chronoamperometry in a medium of KOH 0.1 M dissolved in pure methanol CH3OH. The voltammograms obtained show that the ATT oxidizes anodically at a potential of 1.15 V. The effect of the sweep speed shows that the increase in the sweep speed is accompanied by the increase in the intensity of the first oxidation peak, indicating the acceleration of the process studied, and also indicating that the oxidation reaction of the monomers is essentially irreversible and controlled by a diffusion process. The polymer film analysis by electrochemical impedance spectroscopy shows a capacitive then diffusional behavior—this is a typical effect of conductive polymers. Analysis by EDX justifies the formation of a polymer film on the metal surface. This work was completed by theoretical calculation, which showed that the oxidation of the ATT considerably reduces the energy value of Gap Egap, reaching a value of 2.07 eV—this shows that the polymer film is a semiconductive material.

Molecular (photo)Electrochemical Reduction of CO2 to C1 Products with 2, 4, 6 and 8 Electrons from Mechanistic Studies to Hybrid Systems and Devices

Reduction of carbon dioxide has as main objective the production of useful organic compounds and fuels - renewable fuels - in which solar energy would be stored. Molecular catalysts can be employed to reach this goal, either in photochemical or electrochemical (or combined) contexts. They may in particular provide excellent selectivity thanks to easy tuning of the electronic properties at the metal and of the ligand second and third coordination sphere. Recently it has been shown that such molecular catalysts may also be tuned for generating highly reduced products such as methanol and methane, leading to new exciting advancements.Hybridization of these catalysts with conductive or semi-conductive materials may lead to enhance stability and new catalytic properties, as well as inclusion of molecular catalysts in devices for applications. This approach bridges between homogeneous and heterogeneous, and it raises new fundamental questions that may further lead to breakthrough in CO2 reduction chemistry.Our recent results in these various areas will be discussed, using earth abundant metal (Fe, Co) porphyrins and phthalocyanines as well as related complexes as catalysts.References P. B. Pati, E. Boutin, R. Wang, S. Diring, S. Jobic, N. Barreau, F. Odobel, M. Robert, Nat. Commun. 2020, 11:3499.S. Ren, D. Joulie, D. Salvatore, K. Torbensen, M. Wang, M. Robert, C. Berlinguette, Science 2019, 365, 367-369.E. Boutin, M. Wang, J. C. Lin, M. Mesnage, D. Mendoza, B. Lassalle-Kaiser, C. Hahn, T. F. Jaramillo, M. Robert, Angew. Chem. Int. Ed. 2019, 58, 16172-16176.Z. Guo, C. Cometto, G. Chen, L. Chen, B. Ma, H. Fan, T. Groizard, W-L. Man,S-M. Yiu, K-C. Lau, T-C. Lau, M. Robert, Nat. Catal. 2019, 2, 801-808.H. Rao, L. Schmidt, J. Bonin, M. Robert, Nature 2017, 548, 74-77.C. Costentin, S. Drouet, M. Robert, J-M. Savéant, Science 2012, 338, 90-94.

Efficient photocatalytic aerobic oxidations by a molecular cobalt catalyst linked to mesoporous carbon nitride

The development of green and sustainable oxidative reactions demands efficient catalyst to harness molecular oxygen as a terminal oxidant. In present work, a specific hybrid photocatalyst was rational designed upon covalent grafting a cobalt molecular complex as the electron transfer mediator to mesoporous carbon nitride through an amide linkage. This nanostructured bifunctional photocatalyst was characterized by various spectroscopic techniques and proved to be a selective and efficient catalyst for photocatalytic visible-light-driven aerobic oxidations of organic molecules. This strategy provides efficient electronic communication between the molecular catalyst and semiconductive material, therefore opens a pathway for photocatalytic aerobic oxidations in chemical synthesis.

RETRACTED: Thermodynamic and density functional theory study the removal of different forms of gas arsenic by using aluminum nitride nanotube

In this paper, we characterized the different forms of arsenic (As) in flue gas (FG), which is produced by coal power plants, at varying temperatures using density functional theory (DFT) and thermodynamics computations. Also, the interaction of an aluminum nitride nanotube (AlNNT) with various gaseous species of As was scrutinized. The content of the trivalent As (As3+) was the highest in FG, and the temperature of FG had a significant impact upon the morphological distribution of As3+. The As2O3 molecules primarily had a trigonal bipyramid molecular geometry when the temperature of FF was below 850 K. However, the primary molecular geometry of the As2O3 molecules when the temperature of FG exceeded 850 K was in the following order: chain > trigonal bipyramid. The current study confirmed that the AlNNT is capable of adsorbing As in the FG, and the Al surface had better performance. The current study also theoretically supported the fact that As could be removed from FG produced by coal power plants using the AlNNT as well as other semi-conductive materials as adsorbents.

Surfactant assisted synthesis of nanostructured Mn-doped CuO: An efficient photocatalyst for environmental remediation

The nanostructured Mn-doped CuO material was hydrothermally synthesized using urea as a surfactant to control the shape and size of the material particles. Advanced physiochemical methods were used to look at the microstructure, texture, morphology, and chemistry of the Mn-doped and pristine CuO materials. I–V and UV/visible experiments were performed on doped and un-doped materials to investigate the effect of Mn-doping on electrical conductivity and bandgap. The antibacterial and photocatalytic characteristics of the hydrothermally prepared materials were evaluated and compared through the destruction of Escherichia coli (E.coli) and the photocatalytic mineralization of Rh–B dye. The Mn-doped CuO material has much better photocatalytic activity for the mineralization of Rh–B dye than pristine CuO, with 93.8% dye mineralization after 90 min of visible light illumination compared to 56.52% for pristine CuO. The Mn-doped CuO material mineralized the Rh–B dye at a rate constant (k) of 0.02152 min−1, about three times faster than virgin CuO (k = 0.00802 min−1). The Mn-doped CuO material has negligible electron-hole recombination aptitude but quicker charge transport characteristics than the un-doped comparable based on transient photocurrent and impedance testing. The current work shows how to make a doped semiconductive material that can be used to clean up the environment and is versatile, cheap, and very effective.

Boosting photocatalytic interaction of sulphur doped reduced graphene oxide-based S@rGO/NiS2 nanocomposite for destruction of pathogens and organic pollutant degradation caused by visible light

Semiconductive materials that are activated by solar light and have a low e- and h+ pair recombination rate, a short bandgap, and fast charge carrier characteristics are effective organic pollution treatment catalysts. Synthesizing sulphur doped reduced graphene oxide/NiS2 ([email protected]/NiS2) nanocomposites (NCs) for effective dye-degradation through photocatalysis under solar irradiation is the subject of this paper. [email protected]/NiS2 NCs were made using a simple and efficient [email protected] nanosheets in NiS2 solution technique. When bound to rGO, NiS2 nanoparticles (NPs) act as an effective catalyst for the removal of methylene blue (MB) dye. SEM, EPR, FTIR, UV–vis, photocurrent responses, XRD, and EDX were used to characterize [email protected]/NiS2 NCs. [email protected]/NiS2 is predominantly utilized as a photocatalyst for photoreaction-based degradation of aqueous MB dye. The nanocomposite removes 96 percent of the MB dye in 84 min. The presence of NiS2 NPs in the catalyst increases the formation of hydroxyl radicals (OH), which supports the photocatalytic process by suppressing electron (e-) and hole (h+) recombination, resulting in the destruction of organic contaminants. The catalyst's effectiveness is further tested by altering the pH of the MB solution medium. The reaction rate is pH dependent, with the quickest degradation time in the presence of [email protected]/NiS2 NCs occurring at pH 8. The reusable catalytic characteristics of suspended [email protected]/NiS2 NCs are investigated for six cycles, yielding a degradation efficiency of more than 93 percent in 84 min. Under sunlight, the antibacterial effectiveness of [email protected]/NiS2 was investigated against Gram-positive and Gram-negative microorganisms. These promising findings could be used to purify polluted water from numerous sectors.

Technical Perspectives on Applications of Biologically Coupled Gate Field-Effect Transistors.

Biosensing technologies are required for point-of-care testing (POCT). We determine some physical parameters such as molecular charge and mass, redox potential, and reflective index for measuring biological phenomena. Among such technologies, biologically coupled gate field-effect transistor (Bio-FET) sensors are a promising candidate as a type of potentiometric biosensor for the POCT because they enable the direct detection of ionic and biomolecular charges in a miniaturized device. However, we need to reconsider some technical issues of Bio-FET sensors to expand their possible use for biosensing in the future. In this perspective, the technical issues of Bio-FET sensors are pointed out, focusing on the shielding effect, pH signals, and unique parameters of FETs for biosensing. Moreover, other attractive features of Bio-FET sensors are described in this perspective, such as the integration and the semiconductive materials used for the Bio-FET sensors.

A Comparative Study of Biomimetic Synthesis of EDOT-Pyrrole and EDOT-Aniline Copolymers by Peroxidase-like Catalysts: Towards Tunable Semiconductive Organic Materials.

It has been two decades since biomimetic synthesis of conducting polymers were first reported, however, the systematic investigation of how catalysts influence the properties of the conducting polymers has not been reported yet. In this paper, we report a comparative study between peroxidase-like catalyst, dopants, and their effect on the properties of poly (3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (PPY), and polyaniline (PANI). We also investigate the EDOT-Pyrrole and EDOT-Aniline copolymerization by enzymomimetic synthesis using two catalysts (Ferrocene and Hematin). It was found that, chemically, there are no detectable effects, only having small contributions in molar ratios greater than 0.7–0.3. Spectroscopic data provide solid evidence concerning the effect in the variation of the molar fractions, finding that, as the molar fraction of EDOT decreases, changes associated with loss of the conjugation of the structure and the oxidation state of the chains were observed. The electrical conductivity was considerably modified depending on the type of catalyst. Hematin produces conductive homopolymers and copolymers when doped with p-toluene sulfonic acid (TSA), while ferrocene produces low conductive copolymers under the same conditions. The mole fraction affects conductivity significantly, showing that as the EDOT fraction decreases, the conductivity drops drastically for both EDOT-PY and EDOT-ANI copolymers. The type of dopant also notably affects conductivity; the best values were obtained by doping with TSA, while the lowest were obtained when doping with polystyrene sulfonate (PSS). We also draw a biomimetic route to tailor the fundamental properties of conducting homopolymers and copolymers for their design and scaled-up production, as they have recently been found to have use in a broad range of applications.

A Risk Assessment for Utilities to Prevent Transformer OLTC Failures Caused by Silver Sulphide Corrosion

Silver sulphide corrosion is a recently identified failure mechanism of transformer onload tap changers (OLTC). The corrosive sulphur in transformer oil reacts with the silver coated components of OLTC tap selector and forms silver sulphide films. During OLTC operation, the silver sulphide flakes can be detached from the tap selector and mix with the transformer oil. The silver sulphide is a semi conductive material. As a result, the dielectric strength in the transformer oil around the OLTC silver coated contacts or elsewhere in the transformer, wherever the semi conductive particles travel, will be reduced. Eventually, due to either high electric field stress or aged oil with a low dielectric strength, oil breakdown can occur between adjacent contacts. This can cause a catastrophic failure of the OLTC and quite often the tapping winding as well. Since such failures affect the transformer reliability, utilities are interested in methods of detecting and mitigating silver sulphide corrosion on OLTCs. This paper presents a risk assessment criterion to identify the degree of significance of silver sulphide corrosion in transformers using existing diagnostic techniques.

Fabrication of nanostructured iron-cobalt layered double hydroxide: An innovative approach for the facile synthesis

Studying semiconductive materials-based supercapacitors is significant for developing next-generation energy storage devices. However, the fabrication of a novel semiconductive material-based electrode with self-supporting design, flexible support, and nanoarchitecture is a challenge for the material researcher of 21st century. We present a facile method to fabricate three-dimensional (3D), porous, conductive electrodes based on semiconductive materials with high electrochemical performance. We fabricate the FeCo-LDH sample via hydrothermal route and decorate it on the flexible carbon cloth (CC) to get a flexible and self-supporting electrode. Textural, morphological, elemental, thermal, and functional group studies of the hydrothermally generated powder were performed using XRD, SEM, EDX, TGA, and FTIR methods. Well-known EIS, GCD, and CV tests were used to evaluate the electrochemical possessions of the FeCo-LDH/CC electrode. The performed electrochemical experiments indicated that our manufactured FeCo-LDH/CC electrode has an excellent specific capacity of 1041F/g at 0.5 A/g. Our self-supporting and flexible electrode has excellent cycle stability (it loses only 7.3 percent of its capacity after 5000 GCD cycles). It retains 79.2 percent of its capacitance when the current density increases from 0.5 A/g to 9 A/g. The superior electrochemical activity observed is attributed to the electrode's novel structure and logical design. According to the electrochemical experiment findings, our manufactured FeCo-LDH/CC electrode has great promise for practical applications in next-generation electrochemical capacitors.

Synthesis of Si-Ge Nanosheets and Their Dispersion of Organic Solvents with Focus on the Hansen Solubility Parameters.

Two-dimensional (2D) materials combine the collective advantages of individual building blocks and synergistic properties and have spurred great interest as a new paradigm in materials science. Especially, exfoliation of 2D semiconductive materials into nanosheets is of significance for both fundamental and potential applications. In this report, silicon–germanium (Si–Ge) nanosheets were synthesized by sonication of porous Si–Ge powder. The raw material Si–Ge powder was obtained by leaching Li from Li13Si2Ge2 with ethanol; after that, it was crystallized by heat treatment at 500 °C. The thickness and the lateral size of the exfoliated Si–Ge nanosheets were about 3 nm and a few microns, respectively. The nanosheets were dispersed in 55 different organic solvents, and their Hansen solubility parameters were calculated and compared with those of the end member (Si and Ge) nanosheets and graphene.

Synthesis and Strong π-π Interaction of Hexaazatriphenylene Derivatives with Alternating Electron-Withdrawing and -Donating Groups.

Hexaazatriphenylene (HAT) derivatives have attracted wide attention because of their electron-deficient nature and unique self-assembly properties. In this work, a facile synthesis method for obtaining HAT derivatives with alternating electron-withdrawing nitrile and electron-donating alkoxy groups (HATCNOCn) is proposed. Crystal structure analysis indicated that HATCNOCn forms a one-dimensional columnar structure via strong π-π interactions. Density functional theory calculations revealed that the edge of HATCNOCn is divided into positively and negatively charged sites owing to the presence of alternating nitrile and alkoxy groups, which would induce strong π-π interactions. Thermal analysis and polarizing optical microscopy revealed that HATCNOCn exhibits columnar liquid-crystal phases. Time-resolved microwave conductivity measurements further demonstrated the photoconductive nature of HATCNOCn. The proposed strategy could provide a new strategy for the design of novel organic semiconductive materials.

Wet-chemical synthesis of urchin-like Co-doped CuO: A visible light trigger photocatalyst for water remediation and antimicrobial applications

The semiconductive material must have a large surface area and a visible light active bandgap in order to be selected for photocatalytic applications. Herein, we fabricate an urchin-like CoxCu1-xO photocatalyst with a visible light-triggered bandgap and high surficial properties using nanotechnology, doping, and chemical activation approaches. X-ray diffraction and optical analysis revealed that the CoxCu1-xO sample possesses a high porosity (%) and a visible light active bandgap (1.59 eV). Furthermore, the CoxCu1-xO sample showed greater electrical conductivity than the pristine CuO photocatalyst, which positively influenced the kinetics of the photocatalysis process. The antibacterial and photocatalytic performances of the synthesized materials have been investigated and compared by employing bacterial strains and organic pollutants (Methylene-blue), respectively. The results of the antibacterial assay, conducted on Escherichia coli (E.coli), showed that the CoxCu1-xO sample possessed excellent antibacterial activity. Concerning the photocatalytic activity, we noted that among the doped and undoped materials tested for their Methylene-blue degradation capacity, the CoxCu1-xO catalyst demonstrated outstanding activity with a removal efficiency of 92.6% over 90 min. In contrast, the pristine CuO showed comparatively poor performance, with a removal efficiency of merely 53.75%. The superior photocatalytic activity observed in the case of CoxCu1-xO was attributed to its enhanced surface area, porous surface, good electronic conductivity, lower bandgap, and nanoarchitecture. Our study points towards a potential strategy for preparing a simple and efficient photocatalyst to mineralize dye and kill pathogenic microbes.

Tuning the Electronic and Optical Properties of the Novel Monolayer Noble-Transition-Metal Dichalcogenides Semiconductor β-AuSe via Strain: A Computational Investigation.

The strain-controlled structural, electronic, and optical characteristics of monolayer β-AuSe are systematically studied using first-principles calculations in this paper. For the strain-free monolayer β-AuSe, the structure is dynamically stable and maintains good stability at room temperature. It belongs to the indirect band gap semiconductor, and its valence band maximum (VBM) and conduction band minimum (CBM) consist of hybrid Au-d and Se-p electrons. Au–Se is a partial ionic bond and a partial polarized covalent bond. Meanwhile, lone-pair electrons exist around Se and are located between different layers. Moreover, its optical properties are anisotropic. As for the strained monolayer β-AuSe, it is susceptible to deformation by uniaxial tensile strain. It remains the semiconductor when applying different strains within an extensive range; however, only the biaxial compressive strain is beyond −12%, leading to a semiconductor–semimetal transition. Furthermore, it can maintain relatively stable optical properties under a high strain rate, whereas the change in optical properties is unpredictable when applying different strains. Finally, we suggest that the excellent carrier transport properties of the strain-free monolayer β-AuSe and the stable electronic properties of the strained monolayer β-AuSe originate from the p–d hybridization effect. Therefore, we predict that monolayer β-AuSe is a promising flexible semiconductive photoelectric material in the high-efficiency nano-electronic and nano-optoelectronic fields.