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The compound polyaniline (Poly-ANI) with different concentrations of (H2SO4) sulfuric acid has been synthesized by the chemical polymerization method. The prepared compounds have been characterized using number of techniques including FTIR, FE-SEM, EDS and DSC. Additionally, UV–Vis spectroscopy employed for studying the linear optical properties of polymer with different acid concentrations. Third order optical nonlinearity was characterized using Z-scan at 532 nm. The results showed that the nonlinear refractive index has a negative sign. It was observed that the nonlinear refractive index changes in different ratios of H2SO4. The high value of nonlinear refractive index ( n 2 ) obtained along Z-axis is 74.62 × 10 - 7 cm2/W, and the corresponding χ 3 is 21.5 × 10−5 esu. Also, the Poly-ANI film shows the response to NH3 gas sensing in the range 20 ppm-250 ppm and can be used for NH3 sensing application. [ABSTRACT FROM AUTHOR]

We have developed a theory of dimensional quantization for nanostructures, both one-dimensional and zero-dimensional, constructed from monoatomic layers of transition metal dichalcogenides (TMDCs). This theory has enabled us to derive expressions for the energy spectra of charge carriers in both even and odd states (relative to coordinate inversion), as these states occur within quantum-confined lines and points of the TMDC monoatomic layers, dependent on their geometric dimensions. Our numerical analysis provides a detailed exploration of the quantum-confined energy states of electrons within these nanostructures, offering insights into their potential applications in advanced nanoelectronic devices. This work not only advances our understanding of the energy characteristics of TMDC monoatomic layers but also contributes to the broader field of material science by exploring the effects of dimensional quantization on electronic properties.

We have developed a theory of dimensional quantization for nanostructures, both one-dimensional and zero-dimensional, constructed from monoatomic layers of transition metal dichalcogenides (TMDCs). This theory has enabled us to derive expressions for the energy spectra of charge carriers in both even and odd states (relative to coordinate inversion), as these states occur within quantum-confined lines and points of the TMDC monoatomic layers, dependent on their geometric dimensions. Our numerical analysis provides a detailed exploration of the quantum-confined energy states of electrons within these nanostructures, offering insights into their potential applications in advanced nanoelectronic devices. This work not only advances our understanding of the energy characteristics of TMDC monoatomic layers but also contributes to the broader field of material science by exploring the effects of dimensional quantization on electronic properties. [ABSTRACT FROM AUTHOR]

III-nitride high-electron-mobility transistors (HEMTs) are the optimal choices for high-RF and power applications due to their exceptional performance characteristics. Nevertheless, HEMTs face formidable challenges related to large gate and buffer leakage currents, which inevitably impose significant limitations on device performance and reliability. In response to these challenges, this work studies the design consideration of a T-shaped gate InAlN/AlN with polarized doped buffer HEMT. The simulation results show that the parasitic capacitances are deeply affected by the geometry of the T-gate. The less influence of gate-to-source capacitance (Cgs) by the drain voltage possesses constant depletion charges at the source side, leading to a persistent value of Cgs with drain bias. Moreover, a polarization-doped buffer layer has been incorporated, effectively enhancing the confinement of the two-dimensional electron gas by causing an upward convex bend in the conduction band. This strategic design element significantly contributes to the reduction in leakage current (10−8), positive shift of Vth (0.9 V), and improves the switching ratio (108). The effect of gate head length (Hlength), gate stem height (Sheight), and gate foot length (Flength) on various RF parameters has been investigated. The simulated results confirm that the proper choice of Hlength (280 nm), Sheight (100 nm), and Flength (10 nm) significantly reduced the parasitic capacitance (Cgs = 350 fF/mm and Cgd = 140 fF/mm) and enhanced the Fmax (840 GHz), GBP (636 GHz), Ft (583 GHz) and also improved the power gains. The extracted results of the proposed design exhibit its efficacy for high-performance RF/microwave applications. [ABSTRACT FROM AUTHOR]

A CaMoO4 photocatalyst with high activity for degradation of aureomycin hydrochloride was prepared by sol-gel method. The phase structure, purity, functional group, surface morphology, optical properties and photocatalytic activity of the CaMoO4 photocatalyst were investigated by various characterization methods. The results showed that the CaMoO4 photocatalyst was tetragonal phase, and a small amount of C-O functional groups were present in the sample. The particles were approximately spherical, which consisted of large particles and fine particles. It had high visible-light response with an optical band gap value of 3.21 eV. The photocatalytic activity of CaMoO4 photocatalyst was studied at different drug concentrations, catalyst dosages and pH values using aureomycin hydrochloride as the target for degradation. The results showed that the degradation percentage reached 94% at the drug mass concentration of 200 mg/L, photocatalyst dosage of 1 g/L and pH of 7. The photocatalytic mechanism of the CaMoO4 photocatalyst was proposed based on experimental results and band theory. The mechanism study showed that the C-O functional groups provided extra energy for electron transition to the conduction band of the CaMoO4 photocatalyst and promoted the generation of electron hole pairs. Holes, hydroxyl radicals and superoxide radicals were the key factors to promote the degradation of aureomycin hydrochloride. [ABSTRACT FROM AUTHOR]

Identifying disease biomarkers and detecting hazardous, explosive, flammable, and polluting gases and chemicals with extremely sensitive and selective sensor devices remains a challenging and time-consuming research challenge. Due to their exceptional characteristics, semiconducting metal oxides (SMOxs) have received a lot of attention in terms of the development of various types of sensors in recent years. The key performance indicators of SMOx-based sensors are their sensitivity, selectivity, recovery time, and steady response over time. SMOx-based sensors are discussed in this review based on their different properties. Surface properties of the functional material, such as its (nano)structure, morphology, and crystallinity, greatly influence sensor performance. A few examples of the complicated and poorly understood processes involved in SMOx sensing systems are adsorption and chemisorption, charge transfers, and oxygen migration. The future prospects of SMOx-based gas sensors, chemical sensors, and biological sensors are also discussed. [ABSTRACT FROM AUTHOR]

Abstract Dielectric polymer nanocomposites are considered as one of the most promising candidates for high-power-density electrical energy storage applications. Inorganic nanofillers with high insulation property are frequently introduced into fluoropolymer to improve its breakdown strength and energy storage capability. Normally, inorganic nanofillers are thought to introducing traps into polymer matrix to suppress leakage current. However, how these nanofillers effect the leakage current is still unclear. Meanwhile, high dopant (> 5 vol%) is prerequisite for distinctly improved energy storage performance, which severely deteriorates the processing and mechanical property of polymer nanocomposites, hence brings high technical complication and cost. Herein, boron nitride nanosheet (BNNS) layers are utilized for substantially improving the electrical energy storage capability of polyvinylidene fluoride (PVDF) nanocomposite. Results reveal that the high conduction band minimum of BNNS produces energy barrier at the interface of adjacent layers, preventing the electron in PVDF from passing through inorganic layers, leading to suppressed leakage current and superior breakdown strength. Accompanied by improved Young’s modulus (from 1.2 GPa of PVDF to 1.6 GPa of nanocomposite), significantly boosted discharged energy density (14.3 J cm−3) and charge–discharge efficiency (75%) are realized in multilayered nanocomposites, which are 340 and 300% of PVDF (4.2 J cm−3, 25%). More importantly, thus remarkably boosted energy storage performance is accomplished by marginal BNNS. This work offers a new paradigm for developing dielectric nanocomposites with advanced energy storage performance.

Antimony selenide (Sb2Se3) solar cells often demonstrate current–voltage (J–V) distortion at low temperature, particularly at reverse bias or under red‐light irradiation. A highly doped p‐type (HDP) thin layer between the buffer and absorber layers is typically supposed to induce the J–V distortion. In this work, an analytical model for the experimental Sb2Se3 solar cell has been presented to investigate the effect of the HDP layer characteristics on the J–V distortion. This proposed model can also calculate the critical voltage at which the J–V distortion occurs. The results show that the Sb2Se3 solar cells with the HDP layer have low efficiency when doping concentration and thickness of the HDP layer increase due to a large J–V distortion. This study confirms that the presence of an electron barrier in the conduction band formed by the HDP layer can cause J–V distortion. Hence, the effect of electron barrier height on cell performance based on the derived formulas is investigated. Finally, comparing the simulation and modeling results with variations of the physical and electrical properties of the HDP layer provides a good evaluation for understanding the behavior of Sb2Se3 solar cells. [ABSTRACT FROM AUTHOR]

In this research, molecular modification is employed to see the enhancement in the efficiency of Tyrian Purple (TP), a natural dye, for organic photovoltaic materials. By using Density Functional Theory (DFT) based molecular modeling, seven new structures are designed with pi spacer to extend electron donor moieties. Teheir Frontier Molecular Orbital (FMO) analysis demonstartes their charges with a similar pattern of distributions over their Highest Occupied and Lowed Unocuupied Molecular Orbitals (HOMO/lUMO). This analysls also show their energy gaps (E gaps ) to range around 2.97-3.02 eV. Their maximum absorption wavelength (λ max ) demosntartes 486-490 nm range to indicate their tendency of absorbing light efficiently. Their Transition Density Matrix (TDM) analysis also reveals their facile electronic transitions without a significant charges over spacers. From calculating their photovoltaic paramters, their Light Harvesting Efficiency (LHE) reaches to 72.4-95.5 %. Also their Open Circuit Voltage (V oc ) varies across 1.16-1.34 V. It is found that dyes actively adsorb onto TiO 2 clusters to demonstrate their promise for tuning their Conduction Band (CB). This research is an effort for to evaluate the structural correlations to the develop photovoltaic materials through molecular-level design and optimization., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Identifying disease biomarkers and detecting hazardous, explosive, flammable, and polluting gases and chemicals with extremely sensitive and selective sensor devices remains a challenging and time-consuming research challenge. Due to their exceptional characteristics, semiconducting metal oxides (SMOxs) have received a lot of attention in terms of the development of various types of sensors in recent years. The key performance indicators of SMOx-based sensors are their sensitivity, selectivity, recovery time, and steady response over time. SMOx-based sensors are discussed in this review based on their different properties. Surface properties of the functional material, such as its (nano)structure, morphology, and crystallinity, greatly influence sensor performance. A few examples of the complicated and poorly understood processes involved in SMOx sensing systems are adsorption and chemisorption, charge transfers, and oxygen migration. The future prospects of SMOx-based gas sensors, chemical sensors, and biological sensors are also discussed.

Highlights: High conduction band inorganic layers are manufactured via simple but efficient methodology. The multilayered nanocomposite possesses an outstanding breakdown strength of 611 MV m−1 and an excellent discharged energy density of 14.3 J cm−3, which are 119% and 177% of the randomly dispersed nanocomposite (515 MV m−1, and 8.1 J cm−3). The current work offers a new paradigm for design and production of high energy density flexible dielectric films. Dielectric polymer nanocomposites are considered as one of the most promising candidates for high-power-density electrical energy storage applications. Inorganic nanofillers with high insulation property are frequently introduced into fluoropolymer to improve its breakdown strength and energy storage capability. Normally, inorganic nanofillers are thought to introducing traps into polymer matrix to suppress leakage current. However, how these nanofillers effect the leakage current is still unclear. Meanwhile, high dopant (> 5 vol%) is prerequisite for distinctly improved energy storage performance, which severely deteriorates the processing and mechanical property of polymer nanocomposites, hence brings high technical complication and cost. Herein, boron nitride nanosheet (BNNS) layers are utilized for substantially improving the electrical energy storage capability of polyvinylidene fluoride (PVDF) nanocomposite. Results reveal that the high conduction band minimum of BNNS produces energy barrier at the interface of adjacent layers, preventing the electron in PVDF from passing through inorganic layers, leading to suppressed leakage current and superior breakdown strength. Accompanied by improved Young's modulus (from 1.2 GPa of PVDF to 1.6 GPa of nanocomposite), significantly boosted discharged energy density (14.3 J cm−3) and charge–discharge efficiency (75%) are realized in multilayered nanocomposites, which are 340 and 300% of PVDF (4.2 J cm−3, 25%). More importantly, thus remarkably boosted energy storage performance is accomplished by marginal BNNS. This work offers a new paradigm for developing dielectric nanocomposites with advanced energy storage performance. [ABSTRACT FROM AUTHOR]

Aluminum (Al)‐doped indium zinc magnesium oxide (Al:IZMO)‐based transparent conductive oxide (TCO) films with a tunable conduction band structure are developed via deposition at room temperature under radio‐frequency (RF) magnetron co‐sputtering for the application of highly efficient photovoltaic devices. First, at the amorphous phase region with the [In]/([In] + [Zn]) compositional ratio of 0.5–0.8, Al‐doped indium zinc oxide (Al:IZO) films obtained by introducing a small amount of aluminum oxide (Al2O3) exhibit higher Hall mobility and lower carrier density than those of indium zinc oxide (IZO) without Al doping. Second, adding magnesium oxide (MgO) to Al:IZO allows the optical bandgap (Eg) control, with constant ionization energy of −7.31 eV, which can be expressed by Eg = 0.83y + 3.33 (eV) as a function of [Mg]/([Zn] + [Mg]) compositional ratio (y) (in the y value region of 0–0.12). This result suggests that the conduction band minimum can be tuned by 0.067 eV under the 8% Mg substitution into the Zn site in the Al:IZMO films while remaining valence band maximum. Al:IZMO‐based TCO films with conduction band controllability are deposited at room temperature for preventing thermal damage. These findings contribute to the device design and development of emerging photovoltaic applications. [ABSTRACT FROM AUTHOR]

The DC and RF performance of ultra‐scaled 10 nm E mode InAlN/AlN HEMT with polarized doped buffer has been investigated. The proposed device has the feature of polarized doped buffer, heavily doped source/drain region, and recessed T‐gate structure. The polarization‐induced doping in the buffer layer bent the conduction band upwardly convex, which enhanced the 2DEG confinement, reduced the buffer leakage current, and significantly uplifted the breakdown voltage (33 V), which is 5 times higher than the conventional InAlN/AlN GaN buffer HEMT (8 V). The short channel effect was further reduced by the recessed gate engineering (high on/off ratio 109, subthreshold swing 78 mV/dec, and DIBL 100 mV/V), and smaller 10 nm foot length of T‐gate reduced the parasitic capacitance, which uplifts the RF parameters of the proposed device. The proposed device exhibits a high current density of 2.8 A/mm, transconductance 1.55 S/mm, cutoff frequency fT (583 GHz), and maximum oscillation frequency fmax (840 GHz). At room temperature, the calculated carrier density and mobility are 2.8 × 1013 cm−2 and 1250 cm2/Vs. The large Jhonson figure of merit (fT. VBR) 19.23 THz and (fT. fmax)1/2 699 GHz shows the potential of the proposed device for high‐power millimeter‐wave applications. [ABSTRACT FROM AUTHOR]

[Display omitted] In the semiconductor/molecule/metal system, enhancing the efficiency of the charge-transfer (CT) plays a pivotal role in improving the sensitivity of semiconductor-based surface-enhanced Raman scattering (SERS). In this work, use of SERS for detection of an enhanced CT in a chemically-etched Al-doped ZnO (AZO), 4-mercaptopyridine (MPy) molecule, and Ag nanoparticles (NPs) (AZO/MPy/Ag) sandwich structure is reported. A series of CT routes are proposed in the energy level diagram of AZO/MPy/Ag assemblies under the excitation line at 633 nm. Very interestingly, for the first of its kind, a significant CT route from the conduction band (CB) of AZO to the lowest unoccupied molecular orbital (LUMO) of MPy molecule is detected. This route can remarkably improve the degree of CT in the AZO/MPy/Ag system by about 48% compared with that of the ZnO/MPy/Ag system. Furthermore, the uniquely enhanced CT route is also further confirmed by alternative probe molecules like p-aminothiophenol (PATP) and 4-mercaptobenzoic acid (MBA). The discovery of this extra CT route will inevitably play an irreplaceable role in SERS enhancement through its participating in the CT enhancement mechanism. [ABSTRACT FROM AUTHOR]

The cubic shaped zinc stannate nanocatalyst (ZS-NC) with the average crystallite size of 32.58 nm was prepared by sol-gel method using ZnO and SnO2 as a precursors. The crystal structural composition was investigated through Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and energy dispersive X-ray (EDX). The microstructure analysis was done over scanning electron microscopy (SEM) and the optical property was studied by operating diffuse reflectance spectroscopy (DRS). The rhodamine 6G was degraded in aqueous under the influence of solar light in the presence of ZS-NC and photocatalytic parameters were derived by using a set of equations. It has been observed almost the dye (99.38%) was mineralized in 330 min with degradation rate of 1.281 X 10-2/min. [ABSTRACT FROM AUTHOR]

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The types of three-photon optical transitions in crystals of cubic symmetry, occurring between the bands of spin-orbit splitting and the conduction band, are determined. Expressions are obtained for the matrix elements of the above optical transitions depending on the degree of polarization of the exciting light. [ABSTRACT FROM AUTHOR]

Bismuth iodide oxides have a wide range of applications as visible light photocatalysts in CO 2 reduction reactions. While formation of heterostructures between semiconductors has been actively used to enhance catalytic reduction performance, the functional groups used to improve the separation ability of electron/holes (e-/h+) and surface energy band positions of BiOI surfaces have been rarely mentioned. Here, a new modification strategy was reported to improve the photocatalytic performance using solvents with hydroxyl functional groups to change the surface structure of BiOI hollow microspheres. Intriguingly, the BiOI hollow microspheres functionalized using diethanolamine have a larger negative surface conduction band than BiOI. Thus the photogenerated electron reduction capacity of the diethanolamine-functionalized BiOI is greatly enhanced, which can be obtained from the yield of reduction reaction testing and characterization results. This hydroxyl functional group modified BIOI provides a new strategy for improving photocatalytic performance. The DFT simulation provides a theoretical basis for photocatalytic CO 2 reduction. [Display omitted] • DEA-BiOI exhibited best CH 3 OH production yields 1096 μmol/g cat in 4 h. • Adjusting the surface bismuth atomic structure through OH groups to obtain efficient photocatalytic CO 2 reduction catalysts. • DEA-BiOI hollow microspheres were prepared by hydrothermal method. • DFT theoretical calculations prove that diethanolamine effectively regulates the surface structure of BiOI.. [ABSTRACT FROM AUTHOR]

The spectral-temperature dependence of the coefficient of single-photon absorption of light in crystals of tetrahedral symmetry, due to optical transitions occurring from the spin-orbit splitting zone to the conduction band, is calculated. In this case, the contribution of the coherent saturation effect to the single-photon light absorption coefficient is taken into account. [ABSTRACT FROM AUTHOR]

In this study, the phenotype of Fe‐doped Nano‐C2N monolayer (C2N monolayer) was analysed based on the Perdew‐Burke‐Ernzerh‐solids (PBEsol) functional of First‐principles. The results indicate that the length of Fe‐C bonds is significantly higher than the C‐N bond. For Fe atom doped, the band gap of C2N monolayer system is reduced from 1.811 to 0.384 ev, which increases the activity of electron hopping. Moreover, at Fe‐doped C2N positions, the partial density of states (PDOS) of the C2N monolayer is well overlapped. That indicates that there has a strong interaction between the Fe atom and the C2N monolayer. Furthermore, after doping with Fe atom, C2N monolayer shows better light absorption ability in the ultraviolet and infrared regions. The corresponding conduction band minima (CBM) values in the Fe‐doped C2N monolayer system are lower than that of the pristine C2N monolayer system. In particular, it was lower than the O2/O2•− redox potential, which show that the electrons located in the conduction band have the potential to convert the oxygen molecules into superoxide radicals. Our findings suggest that Fe‐doped C2N monolayer can be a promising material for the novel photocatalytic degradation materials. [ABSTRACT FROM AUTHOR]

In this paper, the authors propose the use of electrostatic doping for n+ drain region formation in Junctionless accumulation mode field effect transistors (JAMFET). This electrostatically doped drain (EDD) JAMFET employs an additional unbiased electrode (auxiliary electrode) of low workfunction on the intrinsic drain region. This technique effectively suppresses the tunneling leakage, thereby reducing IOFF by 6 orders. The tunneling of electrons from valence band of channel to conduction band of drain happens due to enhanced band bending in OFF‐state (VGS = 0 V, VDS = 1 V). The presence of additional electrode in EDD‐JAMFET increases the width of tunnel barrier formed at channel–drain junction in OFF‐state improving the ION/IOFF ratio by 6 orders. The gate length scaling demonstrates that leakage suppression of EDD‐JAMFET is more effective with approximately 3 orders smaller IOFF even at gate length of 5 nm. The performance of graded channel device (GC‐EDD‐JAMFET) by electrostatic doping is also explored. Significant improvements are observed in terms of ION/IOFF, subthreshold slope SS, DIBL and fT. Finally, the analogue parameters such as Transconductance generation factor Gm/ID, Intrinsic gain AV, output conductance GD, and 'Gm/ID × fT' performance metrics are investigated which show significant improvement at small bias current, making it suitable for ultra‐low power applications. [ABSTRACT FROM AUTHOR]

In search for the probability of p-n junction in the quasi-solid (QS) phase in the multi-semiconductor specimen (MSS) altogether with the development of the DSSC electrolyte optimization technique, there are three major things to be considered: 1) the hypothesis for a theoretical redox-conductivity (I p − σ) correlation on the better understanding of advanced cyclic voltammetry (CV) analysis using a mathematical axiom correlation method, 2) the concept of p-n junction possibility based on the solid-phase (SP) hypothetical projection, and 3) the observational and optimization for x-TiO 2 /Cs/KI-I 2. To prove the p-n junction existence in a QS-MSS, we develop a series of methods by using advanced analysis of voltammogram, which are 1) defining the chitosan as a conductive polymer to a certain extent, 2) understanding the influence of different wt% x-TiO 2 on the redox activity of QS-MSS, and 3) the different crystal system of TN(10)†,‡ that are anatase-rutile (a-r) and rutile-anatase (r-a) dominant phase are influencing the I p. Moreover, the analyses consist of a series of modified-dimensionless parameter, ψ , to define the modified-diffusional coefficient, D x 2 , definition and electronical transferal rate, k 0 , as well. Furthermore, the crucial observation is by looking at the valence and conduction band (vb-cb) for each sample, respectively, to determine the position toward the hypothetical projection in the DSSC system later. Moreover, we found that a hypothetical development on the I p −σ modified function is needed. Also, the use of the vb-cb value is crucial to project a unified rule of p-n junction theory approximation from electrolyte to dye. [ABSTRACT FROM AUTHOR]