Semiconductor Characteristics Research Articles

Unlocking low-concentration NH3 gas sensing: An innovative MOF-derived In2O3/Co3O4 nanocomposite approach

Ammonia (NH3) is an odorless gas with a pungent smell that can affect health differently based on exposure and concentration. In this study, indium oxide was decorated with cobalt oxide (In2O3/Co3O4) flower-like nanocomposites (NFs) as gas-sensitive materials, revealing p-type semiconducting characteristics. The detection of ammonia (NH3) at low concentrations is a significant challenge for chemoresistive gas sensors. Porous Co3O4 nanoflowers were combined with In2O3 nanoparticles to form p-n heterojunctions for NH3 detection. The p-n heterojunction effect and the capability of the sub-valent band to hold vacancies within In2O3 nanoparticles effectively inhibit electron-hole recombination and extend the carrier lifetime. The In2O3/Co3O4 = 0.04 ratio-based gas sensor exhibited excellent selectivity, achieving a low detection limit of 500 ppb for NH3 at 250 °C. The rapid diffusion of gas within the porous Co3O4 NSs and In2O3 nanoparticles accounted for the high response (7.72) and fast response/recovery time (92 s/51 s) of the In2O3/Co3O4-based gas sensor to 10 ppm NH3. This study presents a method for fabricating NH3 gas sensors with trace-level detection capabilities by adjusting the band structure of nanoparticles and three-dimensional metal-oxide nanostructures.

Direct bandgap quantum wells in hexagonal Silicon Germanium

Silicon is indisputably the most advanced material for scalable electronics, but it is a poor choice as a light source for photonic applications, due to its indirect band gap. The recently developed hexagonal Si1−xGex semiconductor features a direct bandgap at least for x > 0.65, and the realization of quantum heterostructures would unlock new opportunities for advanced optoelectronic devices based on the SiGe system. Here, we demonstrate the synthesis and characterization of direct bandgap quantum wells realized in the hexagonal Si1−xGex system. Photoluminescence experiments on hex-Ge/Si0.2Ge0.8 quantum wells demonstrate quantum confinement in the hex-Ge segment with type-I band alignment, showing light emission up to room temperature. Moreover, the tuning range of the quantum well emission energy can be extended using hexagonal Si1−xGex/Si1−yGey quantum wells with additional Si in the well. These experimental findings are supported with ab initio bandstructure calculations. A direct bandgap with type-I band alignment is pivotal for the development of novel low-dimensional light emitting devices based on hexagonal Si1−xGex alloys, which have been out of reach for this material system until now.

Investigation of thermodynamic, magnetic, structural and electronic properties of full-Heusler Co2TiZ (Z=Si,Ge,Sn) alloys

Our expedition into the domain of materials science was an immersive journey, where we tapped into the dynamic synergy between density functional theory (DFT) and the FP-LAPW method. Guided by the enigmatic allure of full-Heusler Co2TiZ (Z=Si, Ge, Sn) alloys, our inquiry embarked on a quest marked by extensive analysis and profound discovery. Throughout this meticulous odyssey, we meticulously unraveled the complex tapestry woven by the structural, magnetic, and electronic properties inherent in both cubic CuHg2Ti-type and AlCu2Mn-type structures. Among the myriad revelations unearthed in our expedition, none stood as starkly as the remarkable stability exhibited by the ferromagnetic state, a stark departure from its nonmagnetic counterpart. This stability was further underscored by the presence of integer magnetic moments, serving as a defining characteristic of the ferromagnetic state. As our journey into the heart of materials science progressed, we peeled back layers of complexity to reveal a fascinating dichotomy within the density of states and band structure. Here, we witnessed a symphony of contrasting behaviors: while majority spins embraced semiconductor characteristics, minority spins danced to the metallic tune, painting a vivid portrait of the alloys' intrinsic half-metallic essence. Leveraging the GGA-PBE methodology, our investigation meticulously probed both fundamental and half-metallic gaps, thus unveiling a comprehensive portrait of the materials' electronic landscape. Moreover, our inquiry meticulously preserved a direct band gap at the X → X point, an essential facet imbued with profound implications for the materials' optoelectronic attributes. These insights, far from being confined to the realm of academic curiosity, serve as catalysts for transformative progress in materials design and optimization. By unraveling the intricate interplay between structure and electronic behavior, our findings lay a sturdy foundation for pioneering applications across diverse fields such as spintronics, catalysis, and energy conversion. In summation, our odyssey stands as a beacon guiding the way toward a new epoch of functional materials, poised to transcend the boundaries of technological innovation and unleash unprecedented capabilities across multifarious domains.

Anion replacement effect on the structural, magnetoelectronic, and optical features of all inorganic halide double perovskites K2LiMoX6 (X= Br, I) for spintronic and optical devices

Herein, the geometrical, magnetic, optoelectronic, thermoelectric features of K2LiMoX6 (X = Br, I) have been simulated by DFT. The FP-LAPW approach is employed via Wien2k software. To confirm the thermodynamic and structural stability of the K2LiMoX6 (X = Br, I) compounds, the tolerance factor (τ) and formation enthalpy are calculated. The predicted spin-polarized band structure (BS) and density of states (DOS) display p-type semiconductor character via direct band gap at X-X symmetry points in both spin versions. The ferromagnetic (FM) character was confirmed from magnetic moments (MTot) which are 3.00090, and 3.00014 μB for K2LiMoBr6, and K2LiMoI6, correspondingly. The materials light absorbance was observed in the range of visible to ultraviolet (UV) zone, thereby enhancing their significance for photocell and optoelectronic devices. In addition, both halides exhibit optimal figure of merit (ZT) which make these materials as promising candidates for efficient heat energy conversion technologies. The outcomes of the studied compounds provide a new path for researchers for the applications of spintronic and optical gadgets.

Colorless Near-Infrared Absorbing Dyes Based on B-N Fused Donor-Acceptor-Donor π-Conjugated Molecules for Organic Phototransistors.

The introduction of a colorless function to organic electronic devices allows responses to light in the near-infrared (NIR) region and is expected to broaden the applications of these devices. However, the development of a colorless NIR dye remains a challenge due to the lack of a rational molecular design for controlling electronic transitions. In this study, to suppress the π-π* transitions in the visible region, polycyclic donor-acceptor-donor π-conjugated molecules with boron bridges (Py-FNTz-B and IP-FNTz-B) are designed and synthesized, which contain pyrrole or indenopyrrole as donor units with fluorinated naphthobisthiadiazole (FNTz) as an acceptor unit. The pyrrole end-capped Py-FNTz-B shows an absorption band in the NIR region without distinct visible-light absorption, which has led to the establishment of colorless characteristics. The indenopyrrole end-capped IP-FNTz-B shows a narrow optical energy gap of 0.87eV in films. Time-resolved microwave conductance and field-effect transistors demonstrate the semiconducting characteristics of these molecules, and Py-FNTz-B-based devices function as NIR phototransistors. Theoretical analyses indicate that the combination of a polyene-like electronic structure with orbital symmetry is important to obtain NIR wavelength-selective absorption. This study suggests that a molecular design based on electronic structures can be effective in the development of colorless NIR-absorbing dyes for organic electronics.

Effect of surface composition on the stability of Ti- and V-based oxycarbide and oxynitride MXenes

Oxycarbide MXenes were recently experimentally identified, opening up the possibility of a vast majority of carbon-based MXenes synthesised to date being in fact oxycarbides, wherein some substitutional oxygen atoms are present amid the layers that were previously thought to contain carbon only. Here, using an approach based on density-functional theory, we study the structural, energetic and electronic properties of subsurface substitutional oxygen atoms on the X layers of MXenes of the form M2XT2, with M = Ti, V; X = C, N; and T = none, O or F. According to the calculations, subsurface O is thermodynamically stable in any concentration on all the analysed MXenes.Subsurface substitutional O atoms in the Ti2C MXene are thermodynamically driven towards the surface, leaving behind vacancies and creating local O surface terminations. Given that this process involves a very low energy barrier, we predict that, under conditions suitable for eliminating the surface termination of MXenes, many vacancies on the layers of X atoms should occur.The O-terminated carbide MXenes, Ti2CO2 and V2CO2, are stable with their hexagonal symmetry up to a threshold amount of subsurface O, around 75 %, which is above the maximum experimentally observed concentration, 65 %. The F surface termination stabilizes the hexagonal structure of MXenes, which no longer distort regardless of the presence and amount of subsurface oxygen. This suggests that MXene synthesis routes based on fluorine-containing compounds are the most indicated for synthesising nitride MXenes.The PBE functional predicts the semiconductor characteristics of the Ti2CO2 MXene to be lost in the presence of subsurface O, even a percentage as low as 6 %, the lowest considered in this work. The hybrid HSE06 functional predicts the oxycarbide material to remain a semiconductor, but with a significantly lowered band gap energy with increasing substitutional O content. Nevertheless, both functionals agree that the mixture of C and O atoms between the Ti layers of the Ti2CO2 MXene increases its conductivity. To the best of our knowledge, this MXene has never been confirmed experimentally to behave as a semiconductor probably because the real samples of this MXene contain subsurface oxygen.

Using scalable computer vision to automate high-throughput semiconductor characterization

High-throughput materials synthesis methods, crucial for discovering novel functional materials, face a bottleneck in property characterization. These high-throughput synthesis tools produce 104 samples per hour using ink-based deposition while most characterization methods are either slow (conventional rates of 101 samples per hour) or rigid (e.g., designed for standard thin films), resulting in a bottleneck. To address this, we propose automated characterization (autocharacterization) tools that leverage adaptive computer vision for an 85x faster throughput compared to non-automated workflows. Our tools include a generalizable composition mapping tool and two scalable autocharacterization algorithms that: (1) autonomously compute the band gaps of 200 compositions in 6 minutes, and (2) autonomously compute the environmental stability of 200 compositions in 20 minutes, achieving 98.5% and 96.9% accuracy, respectively, when benchmarked against domain expert manual evaluation. These tools, demonstrated on the formamidinium (FA) and methylammonium (MA) mixed-cation perovskite system FA1−xMAxPbI3, 0 ≤ x ≤ 1, significantly accelerate the characterization process, synchronizing it closer to the rate of high-throughput synthesis.

Insight into structural, electronic, optoelectronic, dynamic, elastic, thermal and magnetic properties of pure and doped LiMgSb by nitrogen: Ab-initio calculations

In this work, ab-initio simulation has been conducted to explore and compare various properties, structural, electronic, optoelectronic, dynamic, elastic and magnetic of the pure bulk unit cell of LiMgSb and substituted by nitrogen (N). Herein, we have optimized the lattice parameter of the structure using the both approximations, generalized gradient approximation (GGA) and self-interaction correction (SIC), finding values of 6.9 and 6.7 Å, respectively. Additionally, the undoped system exhibits characteristics of a non-magnetic P-type semiconductor. The forbidden band of the compound is an indirect one at Γ-X points, aligning with existing literature, and measuring 0.742 eV and 0.95 eV under the GGA and SIC approximations, respectively. We have also investigated how the bandgap varies with the lattice parameter to analyze the influence of atomic interactions on the electronic band structure. Further analyses include the calculation of the energy photon wavelength and refractive index corresponding to the pure LiMgSb band gap. The electronic and dynamic stabilities of the compound have been confirmed through calculations of formation energies and phonon dispersion and total density of states. The bulk modulus, elastic constants, Debye temperature and melting temperature have been determined, indicating elastic stability of the system. Moreover, substitution doping the compound with N in different antisites positions with various concentrations has revealed ferromagnetic stability in Li1-xNxMgSb and LiMg1-xNxSb. Emphasis has been placed on the half-metallic behavior of the doped alloys, with an estimation of the Curie temperature utilizing mean field theory. Hence, the predicted compounds hold potential for multifaceted applications in spintronics and optoelectronics.

Achieving High Operating-Temperature Self-powered X-Ray Detection in Multilayered Hybrid Perovskites through Arylamine Intercalation.

Polar metal halide hybrid perovskites (PHPs) that exhibit outstanding bulk photovoltaic effect (BPVE), excellent semiconductor features, and strong radiation absorption ability, have shown prominent advantages in highly sensitive direct X-ray detection. However, it is still a challenge to explore PHPs with high BPVE temperature ranges, answering the demand of developing thermally stable passive X-ray detection. Herein, by intercalating arylamine into lead tribromide and inducing order-disorder phase transition, a 2D multilayered PHPs (BZA)2(MA)Pb2Br7 (BZPB, BZA = benzylamine, MA = methylamine) is synthesized. BZPB crystallizes in a polar space group Aea2 at a low-temperature phase and demonstrates a significant open-circuit of 0.3V deriving from BPVE under X-ray irradiation. Meanwhile, the strong X-ray absorption coefficient and outstanding carrier transport capability of the bilayered lead halide framework associated with the polar BPVE give BZPB excellent X-ray detection abilities. At 0V bias, the impressive sensitivity of BZPB is 98 µC Gy-1 cm-2. Importantly, the introduction of the rigid BZA ring increases the energy barrier of phase transition and thus dramatically enhances the X-ray detection operating temperature of BZPB up to 409 K without significant performance degradation. This work strongly reveals the great potential of rational design of metal halide hybrid perovskites for X-ray detection applications.

Optimizing charge transport in hybrid GaN-PEDOT:PSS/PMMADevice for advanced application

Organic–inorganic hybrid light-emitting devices have garnered significant attention in the last few years due to their potential. These devices integrate the superior electron mobility of inorganic semiconductors with the remarkable optoelectronic characteristics of organic semiconductors. The inquiry focused on analyzing the optical and electrical properties of a light-emitting heterojunction that combines p-type GaN with organic materials (PEDOT, PSS, and PMMA). This heterojunction is an organic–inorganic hybrid. The procedure entailed utilizing a spin-coating technique to apply a layer of either poly(methyl methacrylate) (PMMA) or a mixture of PMMA and poly(3,4ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT: PSS) onto an indium tin oxide (ITO) substrate. Subsequently, different Nd:YAG laser pulses (200, 250, and 300 pulses) were used to administer a GaN inorganic layer onto the prepared organic layer using a pulsed laser deposition approach. Subsequently, the thermal evaporation technique was employed to deposit an aluminum electrode on the top of the organic and inorganic layers, while laser pulses were fine-tuned for optimal performance. The Hall effect investigation verifies the p-type conductivity of the GaN material. The electroluminescence studies confirmed the production of blue light by the GaN-based devices throughout a range of voltage situations, spanning from 45 to 72 V.

Iridium's influence on the structural, electronic and mechanical characteristics of ZrCo1-xIrxSb half-heusler alloys

Structural, electronic and mechanical properties ofZrCo1−xIrxSbHalf-Heusler alloys with varying x concentrations (x = 0, 0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875, and 1) were studied by performing the exchange-correlation (XC) energy evaluated using the local density (LDA) and generalized gradient (GGA) approximations. The calculated lattice constant, bulk modulus, and band gap energy of the ternary alloy show good agreement with previous theoretical predictions. The results indicate that an increase in Ir atom concentration in the alloy leads to an enlargement of the lattice constant (from 6.10 to 6.36 Å) and bulk modulus (from 138.09 to 149.70 GPa), resulting in increased volume and hardness of the compound. Moreover, the Engel-Vosko generalized gradient approximation (EVGGA) and modified Becke-Johnson (mBJ) schemes were employed to improve the calculations of the band structure and density of states. The studied alloys exhibit semiconductor characteristics, with a direct band gap for both x = 0.75 and x = 0.875 concentrations and an indirect band gap for the rest of the concentrations. The computed elastic constants for ZrCo1−xIrxSb alloys satisfy the requirements for mechanical stability. The VRH approximations have been used to determine the bulk modulus, shear modulus, Young's modulus, Poisson's ratio and Hardness. In addition, we also determined the anisotropy factor, sound velocities and Debye temperature.

Photon-enhanced thermionic emission solar cells based on boron-doped graphene/carbon nanosphere composite aerogel photocathode material

This study employed a two-step hydrothermal reduction process and freeze-drying technique. Initially, carbon nanosphere composite aerogels (CNSs) were synthesized through the hydrothermal reduction of glucose. Subsequently, boron-doped graphene/carbon nanosphere composite aerogel (BGA/CNS) was prepared by utilizing graphene oxide (GO) and boric acid as carbon (C) and boron (B) sources, respectively, in conjunction with CNS. The photo-enhanced thermionic electron emission (PETE) performance of the samples was assessed using a custom-made device. Boron atom doping was found to modulate the bandgap of graphene aerogel and induce P-type semiconductor characteristics, while the addition of CNSs increased its specific surface area, thereby enhancing its photoelectric properties. The results indicated that BGA/CNS-8h exhibited superior PETE effects, with a short-circuit current, open-circuit voltage, and maximum power of 5.81 µA, −2.10V, and −1.57µW.

Design of a new palladium(ii) halide complex as a bio-active material: synthesis, physico-chemical studies, DFT-computations and evaluation of anti-inflammatory, antioxidant and anti-gastric damage activities.

Colorless single crystals of the zero-dimensional hybrid compound, (C6H10N2)2[PdCl6]·2H2O were acquired through the slow evaporation technique. The crystal structure was explored using SC-XRD, which demonstrates that the material crystallizes in the centrosymmetric space group P1̄ of the triclinic system. The density functional theory method at the B3LYP/Lan2mb basis set level was employed to establish the optimized geometry and vibrational frequencies of the title compound. An acceptable correspondence was observed between the results obtained through calculation and the experimental data, including the structure, and IR spectra. The optical characteristics revealed a direct band gap energy of 2.35 eV, validating the semiconductor characteristics of this new material. The results suggest strong agreement with the experimental data and validate the involvement of metal orbitals in defining the HOMO-LUMO boundary. Simultaneous TGA-DTA shows that this material remains solid up to 210 °C. Beyond these temperatures, a gradual decomposition process occurs, extending up to 440 °C and unfolding in several steps. This process entails the liberation of diverse compounds, encompassing organic molecules, and the evaporation of chlorine ions, ultimately leading to the formation of palladium oxide (PdO) as the final product. When given to rats with gastric ulcers at a dose of 100 mg kg-1, these compounds inhibit the key enzyme responsible for neutrophil infiltration as myeloperoxidase (MPO) by 38.7%. The compound also alleviates cellular damage induced by free radicals, demonstrated by a notable 48.3% decrease in thiobarbituric acid reactive substance rates (TBARS) compared to untreated rats. Additionally, these compounds bring about a substantial 30.6% reduction in the surface area of ulcers.

Prediction of two-dimensional carbon nitride materials with semimetal states and flat bands

The search for new two-dimensional (2D) carbon nitride (CN) materials with desirable properties is an important and critical area of research. This study presents a series of 2D CN materials with appealing features such as semimetal or flat bands. By utilizing group theory and graph theory, we perform a random search of the configurational space of 2D CN monolayers, leading to the identification of 721 new CN materials. Extensive density functional theory calculations were then conducted to evaluate their properties. We found that 57 materials exhibit semimetal behavior, while 664 display characteristics of semiconductors and normal metals. Notably, materials such as 51-5-16-C3N-r568 and 55-5-20-C4N-r568 feature topological Dirac semimetals with protected 1D topological boundary states. Moreover, 31 materials possess flat bands near their Fermi level, including two with kagome-like flat bands that induce intrinsic spontaneous magnetization due to partially-occupied flat bands. Our results offer several promising candidates for exploring physical phenomena related to semimetals or flat bands in 2D CN materials.

O-B(F)←N Functionalized Copolymers with Delayed Fluorescence and P-Type Semiconducting Characteristics.

Conjugated polymers with integrating properties of delayed fluorescence and photovoltaic responses simultaneously are scarcely reported due to the generally contradictory requirements for molecular structures to achieve the two properties. Herein, an O-B(F)←N functionalized fused unit (M) with multiple resonance features, small energy gap between lowest singlet excited state (S1) and triplet excited state (T1) (ΔEST = 0.23eV), and delayed fluorescence (τD = 0.75 µs), is designed. Selecting three benzodithiophene (BDT) derivatives as co-units to copolymerize with M, leading to a series of O-B(F)←N embedded polymers also maintaining delayed fluorescence (τD = 0.4-0.5 µs). Moreover, p-type semiconductor characteristics are tested for these polymers with hole mobilities in the range of 10-6-10-5 cm2/Vs. Devices with obviously photovoltaic responses are prepared using these polymers as donors and Y6 as the acceptor, affording a preliminary efficiency of 5.05%. This work successfully demonstrates an effective strategy to design conjugated polymers with integrating properties of delayed fluorescence and photovoltaic performance simultaneously by introducing O-B(F)←N functional groups to polymer backbones.

Wide-range resistivity characterization of semiconductors with terahertz time-domain spectroscopy

Resistivity is one of the most important characteristics in the semiconductor industry. The most common way to measure resistivity is the four-point probe method, which requires physical contact with the material under test. Terahertz time domain spectroscopy, a fast and non-destructive measurement method, is already well established in the characterization of dielectrics. In this work, we demonstrate the potential of two Drude model-based approaches to extract resistivity values from terahertz time-domain spectroscopy measurements of silicon in a wide range from about 10−3 Ωcm to 102 Ωcm. One method is an analytical approach and the other is an optimization approach. Four-point probe measurements are used as a reference. In addition, the spatial resistivity distribution is imaged by X-Y scanning of the samples to detect inhomogeneities in the doping distribution.

Realizing Weak Light Detection in a 2D Dielectric Switching Hybrid Perovskite Incorporating Dimethylamine

Abstract2D organic–inorganic hybrid perovskites (OIHPs) are regarded as potential candidates for the advancement of multifunctional phase‐transition materials due to their ability to integrate flexible functionality and superior electronic features from both organic and inorganic components. However, the development of 2D OIHPs with dielectric switches and weak light detection capability that are crucial for high‐resolution sensing and imaging, remains challenge. Herein, a novel 2D OIHP BDADMAPb2Br7 (1, BDA = 1,4‐butanediamine and DMA = dimethylamine) is presented, featuring a 2D Dion–Jacobson (DJ) bilayered structure incorporated with secondary amine. Upon heating and cooling cycles, 1 demonstrates long‐term reversible dielectric switching properties at 328 K. Meanwhile, 1 also shows compelling semiconductor characteristics, including a low dark current of 2.87 × 10−11 A (10 V), a large switching ratio of 4 × 103, and a high detectivity of 1.3 × 1012 Jones. In addition, the photodetector based on 1 exhibits an excellent weak light detection ability of 340 nW cm−2 at 405 nm. Such a 2D OIHP demonstrates a novel platform for creating multifunctional materials and significantly promotes the development of integrated devices.

Peculiarities of magnetoresistance in GaAs whiskers at low temperatures

Magnetoresistance of GaAs whiskers with concentrations in the vicinity to metal-insulator transition (MIT) 1017–1018 cm−3 were studied at low temperatures and high magnetic fields (up to 14 T). The whiskers were doped with Te during the growth. The whisker diameter ranges from 10 to 40 μm. Temperature dependence of the whisker resistance have shown metallic and semiconductor character in the proximity to MIT from various sides of the transition. Depending on doping level the character of the whisker magnetoresistance changes from linear positive to quadratic negative. The magnetoresistance of metallic whiskers is explained in terms of weak antilocalization (WAL) model. The specimens with semiconductor character of conductance revealed negative magnetoresistance, magnitude of which rises due to moving away from MIT and reach 15% for the whiskers with concentration 1017 cm−3. The possible reasons of the negative magnetoresistance are discussed. The effect observed is attributed to weak localization (WL) of charge carriers in the region of hopping conductance for the whiskers in the vicinity to MIT. A high negative magnetoresistance (NMR) for the whiskers of low dopant concentration is connected with subsurface conductance in the disordered upper layers of the whiskers due to their core-shell structure.

On the importance of varying device thickness and temperature on the outcome of space-charge-limited current measurements

Space-charge-limited current (SCLC) measurements are commonly employed to characterize charge-transport properties of semiconductors used in next-generation thin-film optoelectronics, such as organic π-conjugated small molecules and polymers, and metal-halide perovskites. Despite the wide-spread adoption of the method, there is no community-wide consensus around how SCLC measurements should be performed, nor how the data should be analyzed and reported. While it is common to report device characteristics by employing a simplistic analytical model for fitting a single J-V curve obtained from a solitary device at room temperature—sometimes in a very select voltage range—expectedly, such an approach will often not give an accurate picture of the underlying physics. On that account, we here aim to highlight the importance of reporting values extracted from not just a solitary single-carrier device measured at room temperature, but from devices with different thicknesses measured at varying device temperature. We also highlight how the choice of device thickness is especially critical in determining what device and material characteristics can be extracted from SCLC measurements, and how this choice can greatly affect the conclusions drawn about the probed semiconducting material. While other factors could affect the outcome of an SCLC measurement and the subsequent analysis, we hope that the topics covered in this article will result in overall improved charge-transport characterization of thin-film semiconductors and initiate a broader discussion into SCLC metrology at large.

Establishing the NiMo6Se8 Chevrel Phase as a Promising Material Using DFT

AbstractIn this study, the NiMo6Se8 Chevrel phase is analyzed using Density Functional Theory (DFT) and the Vienna Ab‐initio Simulation Package (VASP). The analysis focuses on the phase's structural, electrical, and mechanical characteristics to fill gaps in the current literature. The presence of a rhombohedral crystal structure confirms its thermodynamic stability, as indicated by a negative formation enthalpy, which suggests that it can be synthesized under favorable conditions. The electronic properties of the phase are analyzed, indicating that it exhibits semiconductor characteristics with a bandgap of 1.07 eV. This makes it appropriate for various technological applications. The estimated elastic constants provide an indication of mechanical strength and flexibility, with a noticeable presence of anisotropic elasticity. The confirmation of dynamical stability is achieved by analyzing the phonon dispersion curve, which reveals the absence of any negative frequencies. Furthermore, the material has a low thermal conductivity, increasing its suitability for thermoelectric applications. The analysis emphasizes the versatile capabilities of the NiMo6Se8 Chevrel phase, especially in thermoelectric and energy storage applications, showcasing its promising potential for future technological implementation.