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β-Ga2O3, an emerging wide bandgap semiconductor material, holds significant potential for various applications. However, challenges persist in improving the crystal quality and achieving controllable doping of β-Ga2O3. In particular, the relationship between these factors and the mechanisms behind them are not fully understood. Molecular beam epitaxy (MBE) is viewed as one of the most sophisticated techniques for growing high-quality crystalline films. It also provides a platform for studying the effects of doping and defects in heteroepitaxial β-Ga2O3. In our study, we tackled the issue of Si source passivation during the MBE growth of Si-doped β-Ga2O3. We did this by using an electron beam vaporize module, a departure from the traditional Si effusion cell. Our research extensively explores the correlation between Si doping concentration and film properties. These properties include microstructure, morphology, defects, carrier conductivity, and mobility. The results from these investigations are mutually supportive and indicate that a high density of defects in heteroepitaxial β-Ga2O3 is the primary reason for the challenges in controllable doping and conductivity. These insights are valuable for the ongoing development and enhancement of β-Ga2O3-based device techniques. [ABSTRACT FROM AUTHOR]

The rising temperature due to a self-heating or thermal environment not only degrades the subthreshold performance but also intensifies thermal stress, posing a severe challenge to device performance and reliability design. The thermal stress effects on the ON-state performance of the p-type fin field-effect transistor were previously studied. However, as far as we know, how thermal stress affects its subthreshold conduction remains unclear, which is studied in this manuscript. The impact of thermal stress due to the self-heating of adjacent devices on subthreshold conduction is investigated by solving the quantum transport, thermal conduction, and force balance equations for ballistic transport and dissipative transport with phonon scattering. Then, the thermal stress effects at different ambient temperatures are further discussed and analyzed. The simulation results show that the OFF-state leakage current can be reduced by thermal stress, even up to 9.28% for the (110)/[001] device operating at an ambient temperature of 550 K, and its reduction is the comprehensive result of the thermal stress effects on the band structure, potential profile, carrier distribution, and source-to-drain tunneling. In addition, the thermal stress has no significant effects on subthreshold swing although it can change the magnitude of the subthreshold current. Moreover, the effect of thermal stress on subthreshold conduction is highly dependent on the thermal environment of the device and the crystal orientation of the channel semiconductor material. [ABSTRACT FROM AUTHOR]

The practical use of 4H-SiC as a semiconductor material alternative to Si has been investigated by several researchers. However, a key challenge impeding its practical implementation is the elimination of killer defects in the epitaxial layer, such as basal plane dislocations (BPDs), which cause bipolar degradations. The conversion of BPDs into threading edge dislocations is crucial to reduce detrimental mobile dislocations. However, their underlying atomistic mechanisms remain unclear. In this study, the effects of the step height and distance from the step on the contraction of BPDs were determined using a reaction pathway analysis. Notably, the step height did not affect the contraction, and the activation energies for the contraction of the partial dislocation pairs with Burgers vectors closed toward the step were 0.4 (C face) and 0.3 eV (Si face) lower than those for expansion. Conversely, for the partial dislocation pairs with Burgers vectors open toward the step, the activation energies for contraction were 0.4 (C face) and 0.2 eV (Si face) higher than those for expansion. Furthermore, the effect of the step diminished when the distance from the step exceeded 3 nm. The results suggest that the steps prevented contraction, and longer terraces reduced this preventive effect. Therefore, a surface morphology with fewer steps and longer terraces would increase the conversion rate. Furthermore, a low-off-angle substrate and surface polishing would increase the conversion rate, whereas step bunching slightly would decrease it. Macrosteps would decrease the conversion rate as the average distance from the surface to BPDs increased. [ABSTRACT FROM AUTHOR]

This work presents a 3D quantum mechanics based model to address the physics at band structure crossing/anti-crossing points in full band Monte Carlo (FBMC) simulations. The model solves the Krieger and Iafrate (KI) equations in real time using pre-computed coefficients at k -points spatially sampled within the first Brillouin zone. Solving the KI equations in real time makes this model applicable for all electric fields, which enables its use in FBMC device simulations. In this work, a two-level refinement scheme is used to aggressively sample regions in proximity to band crossings for accurate solutions to the KI equations and coarsely sample everywhere else to limit the number of k -points used. The presented sampling method is demonstrated on the band structure of silicon but is effective for the band structure of any semiconductor material. Next, the adaptation of the fully quantum KI model into the semi-classical FBMC method is discussed. Finally, FBMC simulations of hole transport in 4H silicon carbide with and without the KI model are performed. Results along different crystallographic directions for a wide range of electric fields are compared to previously published simulation and experimental values. [ABSTRACT FROM AUTHOR]

This Perspective focuses on experimental and theoretical aspects of positron annihilation spectroscopy. This set of methods is highly suitable for identifying and quantifying vacancy-type defects in semiconductors and also allows for analyzing their physics characteristics. We present selected examples from the past decade, where the methods have been used for obtaining timely and useful insights into the defect-controlled phenomenon in narrow-gap (Ge, GaSb) and wide-gap (III-nitride, oxide) semiconductors. We also discuss possible future developments that may allow more detailed studies in novel semiconductor materials and devices with ever more complex lattice structures. [ABSTRACT FROM AUTHOR]

Radiation damage in semiconductor materials is a crucial concern for electronic applications, especially in the fields of space, military, nuclear, and medical electronics. With the advancements in semiconductor fabrication techniques and the trend of miniaturization, the quality of semiconductor materials and their susceptibility to radiation-induced defects have become more important than ever. In this context, machine learning (ML) algorithms have emerged as a promising tool to study minor radiation-induced defects in semiconductor materials. In this study, we propose a sensitive non-destructive technique for investigating radiation-induced defects using multivariate statistical analyses combined with Raman spectroscopy. Raman spectroscopy is a contactless and non-destructive method widely used to characterize semiconductor materials and their defects. The multivariate statistical methods applied in analyzing the Raman spectra provide high sensitivity in detecting minor radiation-induced defects. The proposed technique was demonstrated by categorizing 100–500 kGy irradiated GaAs wafers into samples with low and high irradiation levels using linear discrimination analysis ML algorithms. Despite the high similarity in the obtained Raman spectra, the ML algorithms correctly predicted the blind testing samples, highlighting the effectiveness of ML in defect study. This study provides a promising approach for detecting minor radiation-induced defects in semiconductor materials and can be extended to other semiconductor materials and devices. [ABSTRACT FROM AUTHOR]

For over half a century, traditional silicon-based integrated circuits (ICs) have been the basis of computational electronics and are widely used in computers, cell phones, and other fields. With the rapid development of human society, silicon-based semiconductor technology is approaching its physical and engineering limits. Our increasing diversity of non-traditional computing needs, such as ultra-small, ultra-fast, ultra-low-power wearables, and space radiation protection, is driving the search for new electronic materials. Semiconducting single-walled carbon nanotubes (s-SWCNTs) have many excellent electrical properties, such as high carrier mobility and high ballistic transport, making them strong candidates for new semiconductor materials in the post-Moore era. Carbon-based electronic technology has been developed for over 20 years, and the fundamental issues such as the material purification of s-SWCNTs, preparation prospects of s-SWCNT-based field-effect transistors (CNT FETs), and device physics based on CNT FETs have been basically solved. However, the chiral diversity of s-SWCNTs may lead to problems such as fluctuations in the electrical performance of CNT FETs, limiting the application of s-SWCNTs in high-end ICs. Monochiral s-SWCNTs not only have excellent electrical properties but also have a controllable structure and uniformity, which are crucial for the high-end IC of CNTs. However, some problems exist in the purity and yield of monochiral s-SWCNT preparation and the optimization of monochiral CNT FETs. Therefore, the chiral sorting of CNTs is reviewed in this paper, and the progress of polymer reprocessing in chiral separation is highlighted. Then, the research progress of monochiral CNT FETs is introduced, and possible development directions are summarized and analyzed. Finally, the application prospects of chiral-enriched s-SWCNTs include challenges and future opportunities. [ABSTRACT FROM AUTHOR]

This paper reviews the evolution of the charge pumping (CP) technique and its applications from the micrometer-scale to the atomic-scale device era. We describe the more significant milestones of the CP technique (CPT) over the past couple of decades, giving insight into its potentialities. We start with the most popular one "traditional or conventional CP" and follow up with its different extensions in various fields like transistor reliability and radiation damage characterizations in devices fabricated with old and new semiconductor and dielectric materials. We show its easy adaptability for transistors with specific geometries. Advantages, weaknesses, as well as future tendencies of CPT and its variants, are also discussed. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) ferrovalley semiconductor materials with intrinsic spontaneous valley polarization offer new prospects for valley electronics applications. However, there are only a limited number of known promising candidate materials, which are in urgent need of expansion. In particular, the room-temperature 2D ferrovalley materials are still lacking. In this study, we predicted novel 2D ferromagnetic CeX 2 (X=Fe,Cl,Br) monolayers by using first-principles calculations. The monolayer CeX 2 is a bipolar magnetic semiconductor with robust dynamical and thermal stabilities, and easy magnetization direction is in the plane. Due to the simultaneous breaking of both inversion symmetry and time-reversal symmetry, the monolayer CeX 2 is exhibiting a spontaneous intrinsic valley polarization when magnetized along the out-of-plane z direction. Interestingly, monolayer CeBr 2 is a spontaneous intrinsic ferrovalley material with a room temperature of 334 K and an obvious valley splitting of 32 meV. Due to the non-zero valley-contrast Berry curvature, monolayer CeBr 2 is a candidate materials for realizing the anomalous valley Hall effect under a suitable applied electric field. Our study provides a theoretical reference for the design of valley electronic devices with anomalous valley Hall effect based on hole-doped CeX 2. [ABSTRACT FROM AUTHOR]

We investigate microlenses that selectively focus the light on only a small fraction of all nanowires within an arrayed InP nanowire solar cell. The nano-concentration improves both the short-circuit current (J s c ) and the open-circuit voltage (V o c ) of the solar cell. For this purpose, polymethyl methacrylate microlenses with 6 μm diameter were randomly positioned on top of an arrayed nanowire solar cell with 500 nm pitch. The microlenses were fabricated by first patterning cylindrical micropillars, which were subsequently shaped as lenses by using a thermal reflow process. The quality of the microlenses was experimentally assessed by Fourier microscopy showing strong collimation of the emitted photoluminescence. By analyzing the slope of the integrated photoluminescence vs excitation density, we deduce a substantial enhancement of the external radiative efficiency of a nanowire array by adding microlenses. The enhanced radiative efficiency of the lensed nanowire array results in a clear enhancement of the open-circuit voltage for a subset of our solar cells. The microlenses finally also allow to increase the short-circuit current of our relatively short nanowires, providing a route to significantly reduce the amount of expensive semiconductor material. [ABSTRACT FROM AUTHOR]

Semiconductor alloy materials are highly versatile due to their adjustable properties; however, exploring their structural space is a challenging task that affects the control of their properties. Traditional methods rely on ad hoc design based on the understanding of known chemistry and crystallography, which have limitations in computational efficiency and search space. In this work, we present ChecMatE (Chemical Material Explorer), a software package that automatically generates machine learning potentials (MLPs) and uses global search algorithms to screen semiconductor alloy materials. Taking advantage of MLPs, ChecMatE enables a more efficient and cost-effective exploration of the structural space of materials and predicts their energy and relative stability with ab initio accuracy. We demonstrate the efficacy of ChecMatE through a case study of the InxGa1−xN system, where it accelerates structural exploration at reduced costs. Our automatic framework offers a promising solution to the challenging task of exploring the structural space of semiconductor alloy materials. [ABSTRACT FROM AUTHOR]

An efficient carrier compensation mechanism in semiconductor layers by Fermi-level engineering is demonstrated using the modulation-doping of a deep acceptor and a shallow donor. The punch-through of the depletion region across the whole stack of modulation-doped layers shifts the Fermi level closer toward the midgap position, resulting in the compensation of residual background free carriers. The method represents an alternative to achieve semi-insulating properties in semiconductor materials where a suitable deep acceptor or donor state at the midgap position is not available. We demonstrate the applicability of the concept with a commercially important GaN case study using carbon (deep acceptor) and Si (shallow donor) doping. A strong enhancement of breakdown field strength and reduced charge pileup effects are observed due to the efficient pinning of the Fermi level. [ABSTRACT FROM AUTHOR]

The accurate measurement of the thermal conductivity in a wide range of semiconductors is of great importance for applications like power electronic devices, which is, however, quite challenging. Current measurement methods suffer from limited measurement range, non-accuracy, complexity, etc. We report in this work an effective in situ method for thermal conductivity measurement based on laser-excited Raman spectroscopy, which has the advantages of non-contact, non-destructive, facile preparation, easy operation, and the capability of a large measurement range. The critical relationship parameters correlating Raman peak shifts and temperature change can be extracted by monitoring and fitting the Raman peak movement at different temperatures. Here, the laser with the micrometer scale spot serves as a Raman scattering source and a heat source for the samples. The thermal conductivity of Si, SiC, polycrystalline diamond, and single crystalline diamond at room temperature was determined to be 140.2 ± 14.4, 414.7 ± 26.2, 1372.3 ± 229.0, and 1734.9 ± 280.6 W/(m K), respectively, which are in good agreement with the theoretical prediction. The temperature distribution of the samples was simulated by the finite element method, which confirms the experimental data. These results highlight the feasibility, reliability, and versatility of Raman spectroscopy for measuring semiconductor materials, particularly those with high thermal conductivity. This is of great interest for exploring semiconductor physics and practical applications like power electronic devices. [ABSTRACT FROM AUTHOR]

A novel model is presented in this study for the situation of wave interference in a non-local stimulated semiconductor medium, including thermal, plasma, and elastic waves. Moisture diffusion in one dimension (1D) has been included in the governing equations by varying the non-local medium's thermal conductivity under the impact of laser pulse according to the non-Gaussian temporal profile. The dimensionless model was characterized by linear transformations. Analytical solutions were obtained by applying Laplace transforms to a description of the governing equations based on the photo-thermoelasticity theory based on moisture diffusivity and variable thermal conductivity. When applying certain of the circumstances (thermal ramp type and non-Gaussian plasma shock), linear solutions are achieved in the time domain using various numerical techniques based on inverse Laplace transforms. Some of the physical variables being studied are visually shown via numerical simulation. The present investigation has produced numerous important concrete instances. Using graphs and theoretical descriptions, several contrasts are drawn, while certain physical factors, such as relaxation durations, changing thermal conductivity, non-local parameters, and reference moisture values, are in play. [ABSTRACT FROM AUTHOR]

Water-assisted ultrashort laser pulse processing of semiconductor materials is a promising technique to diminish heat accumulation and improve process quality. In this study, we investigate femtosecond laser ablation of deep trenches in GaAs, an important optoelectronic material, using water and ambient air environments at different laser processing regimes. We perform a comprehensive analysis of ablated trenches, including surface morphological analysis, atomic-resolution transmission electron microscopy imaging, elemental mapping, photoluminescence, and Raman spectroscopy. The findings demonstrate that GaAs ablation efficiency is enhanced in a water environment while heat-accumulation-related damage is reduced. Raman spectroscopy reveals a decrease in the broad feature associated with amorphous GaAs surface layers during water-assisted laser processing, suggesting that a higher material quality in deep trenches can be achieved using a water environment. [ABSTRACT FROM AUTHOR]

In this study, the formation of nano-porous/fibrous structures was investigated by spot-ion irradiation on Ge and GaSb substrates to consider the formation range of nanostructures and point defects. Spot-ion irradiation was performed in a focused ion beam system with a beam diameter of 35.1 nm, which is determined by the system. The fluence and ion beam current ranged within 5 × 1019–1 × 1022 ions/m2 and 500–520 pA, respectively. All the irradiated ions were Ga+ with incident energy adjusted at 30 keV, and the angle of incidence to the surface normal was 0°. The interval of the irradiated spot ranged from 100 to 1000 nm. For line-patterned irradiations, these spots overlapped with one another at an overlap ratio of 50%, producing a 35.1 nm × 10 μm irradiated region. Result shows that nanostructured regions followed a spot interval. When an interval was shorter than 200 nm, each nanostructured spot coalesced with neighbors to form large and uniform structures. Furthermore, line-patterned irradiation indicated that the migration distance of vacancy was ∼300 nm at maximum, which is consistent with the coalescence phenomenon. [ABSTRACT FROM AUTHOR]

The present work comprises a practical tutorial on the topic of correlative microscopy and its application to optoelectronic semiconductor materials and devices. For the assessment of microscopic structure–property relationships, correlative electron microscopy, combined also with scanning-probe and light microscopy, exhibits a collection of indispensable tools to analyze various material and device properties. This Tutorial describes not only the various microscopy methods but also the specimen preparation in detail. Moreover, it is shown that electron microscopy can serve to monitor phase segregation processes on various length scales in semiconductor nanoparticles and thin films. Algorithms used to extract phase information from high-resolution transmission electron micrographs are explained. [ABSTRACT FROM AUTHOR]

A series of pentagonal bipyramidal anionic germanium clusters doped with heavy rare earth elements, REGe6− (RE = Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), have been identified at the PBE0/def2‐TZVP level using density functional theory (DFT). Our findings reveal that the centrally doped pentagonal ring structure demonstrates enhanced stability and heightened aromaticity due to its uniform bonding characteristics and a larger charge transfer region. Through natural population analysis and spin density diagrams, we observed a monotonic decrease in the magnetic moment from Gd to Yb. This is attributed to the decreasing number of unpaired electrons in the 4f orbitals of the heavy rare earth atoms. Interestingly, the system doped with Er atoms showed lower stability and anti‐aromaticity, likely due to the involvement of the 4f orbitals in bonding. Conversely, the systems doped with Gd and Tb atoms stood out for their high magnetism and stability, making them potential building blocks for rare earth‐doped semiconductor materials. [ABSTRACT FROM AUTHOR]

As a semiconductor material, g-C 3 N 4 has attracted attention with proficient charge storage and transfer characteristics. However, there is a limitation in its applications because of the low specific surface area and the small number of active sites associated with the bulk structure, and there is a lack of in-depth understanding of its optical properties. In this paper, we have discussed four different morphologies of g-C 3 N 4 , including bulk (B–CN), hexagonal hollow tubular (T-CN), alveolate (A-CN), and hollow spherical (S–CN) that have been prepared using the supramolecular self-assembly strategy. To examine the changes in morphology that affect the physiochemical and optical properties of the g-C 3 N 4. With the change in the ratio of the raw materials and reaction condition, the number of defects in g-C 3 N 4 represented by uncondensed NH 2 /-NH groups changes, thus inhibiting the recombination of photogenerated carriers. Meanwhile, the changes in morphology affect the microstructural composition of g-C 3 N 4 , which changes the energy band positions and fluorescence properties of the material. This work provides some valuable information on the morphological regulation of g-C 3 N 4 and how to modulate the morphology to change the properties of g-C 3 N 4. • The successful preparation of g-C 3 N 4 with different morphologies. • The successful regulation of defective sites represented by NH 2 /-NH groups. • The individual bandgap states of the material were altered by modulating the morphology of g-C 3 N 4. • The influence of the microstructure of g-C 3 N 4 on its optical properties is deeply understood. [ABSTRACT FROM AUTHOR]

A unique ZnIn 2 S 4 /BiFeO 3 piezoelectric enhanced step-scheme heterojunction was fabricated; the synergistic enhancement of the internal electric field generated in the heterojunction and the alternating piezoelectric field generated in BiFeO 3 induced an exceptional hydrogen evolution rate under the co-excitation of ultrasonic treatment and visible-light irradiation. [Display omitted] An emerging approach that employs both light and vibration energy on binary photo-/piezoelectric semiconductor materials for efficient hydrogen (H 2) evolution has garnered considerable attention. ZnIn 2 S 4 (ZIS) is recognized as a promising visible-light-activated photocatalyst. However, its effectiveness is constraint by the slow separation dynamics of photoexcited carriers. Density functional theory (DFT) predictions have shown that the integration of piezoelectric BiFeO 3 (BFO) is conducive to the reduction of the H 2 adsorption free energy (ΔG H*) for the photocatalytic H 2 evolution reaction, thereby enhancing the reaction kinetics. Informed by theoretical predictions, piezoelectric BFO polyhedron particles were successfully synthesized and incorporated with ZIS nanoflowers to create a ZIS/BFO heterojunction using an ultrasonic-assisted calcination method. When subjected to simultaneous ultrasonic treatment and visible-light irradiation, the optimal ZIS/BFO piezoelectric enhanced (piezo-enhanced) heterojunction exhibited a piezoelectric photocatalytic (piezo-photocatalytic) H 2 evolution rate approximately 6.6 times higher than that of pristine ZIS and about 3.0 times greater than the rate achieved under light-only conditions. Moreover, based on theoretical predictions and experimental results, a plausible mechanism and charge transfer route for the enhancement of piezo-photocatalytic performance were studied by the subsequent piezoelectric force microscopy (PFM) measurements and DFT calculations. The findings of this study strongly confirm that both the internal electric field of the step-scheme (S-Scheme) heterojunction and the alternating piezoelectric field generated by the vibration of BFO can enhance the transportation and separation of electron-hole pairs. This study presents a concept for the multipath utilization of light and vibrational energy to harness renewable energy from the environment. [ABSTRACT FROM AUTHOR]

Semiconductor heterojunctions are an effective way to achieve efficient photocatalysts, as they can provide an adequate redox potential with visible light excitation. Several works have reported synergistic effects with nanoparticle semiconductor materials. The question is still open for thin film heterojunctions formed by stacked layers, as photocatalysis is considered a surface phenomenon. To investigate if the internal layer really affects or modifies the photocatalytic properties of the external material, we analyze the thin film heterojunction with ZnO and Bi2O3 semiconductors deposited by spray pyrolysis in two configurations: substrate/ZnO/Bi2O3 and substrate/Bi2O3/ZnO. Microstructural analysis was performed to verify the formation of the physical junction of the materials and discard new ternary phases. The photocatalytic activity was analyzed as a function of the thickness of the layers under blue light irradiation. We determined the conduction and valence bands positions, the carrier concentrations, mobilities, Fermi levels, etc. that allowed us to distinguish two reaction mechanisms depending on the configuration. There is a strong compromise between the order and thickness of the layers with the photocatalytic activity. The internal electric field produced in the interface defines the route of the photogenerated charges, and therefore the photocatalytic response. Thus, well-designed thin film heterojunctions can indeed improve the photocatalytic activity of the surface layer. [ABSTRACT FROM AUTHOR]

We report the synthesis of sulfonated copolyaniline/polysafranin/L-ascorbic acid/Ag@SiO2 fine powdered nanocomposites and investigate the influence of incorporating the dye on their conductivity. The composite was characterized via IR, UV, cyclic voltammetry (CV), electric, dielectric, SEM, TEM, TGA and DSC measurements. Microscopy images revealed intensified spherical particles that were dispersed across the entire surface, and the SiO2/Ag particles were distributed on the surface. The XRD results exhibited peaks at many 2q values, and their interatomic spacing (d) and crystallite (grain) sizes were calculated. The thermal degradation curves exhibited an interesting model of stability. The cyclic voltammogram exhibited redox peaks identical to those of the reported analogues. The d.c. conductivity of the oligomer varied from 0.06 − 0.016 (s/cm), and that of the composite varied from 0.008 to 0.016 (s/cm). The material changed from a semiconductor to a metallic material. The observed conductivity is mainly attributed to self-doping between the sulfonate groups and the charged nitrogen atoms in the polymer chains. The frequency dependence of the permittivity, ε′, showed a marked effect on the frequency window under consideration. The permittivity, ε′, is independent of the increase in the frequency of the oligomer and the composite. This behavior supports the non-Debye dependency by confirming the occurrence of electrode polarization and space charge effects. In conclusion, the incorporation of safranin dye with a thermally stable, highly sulfonated polyaniline derivative/Ag@SO2 nanocomposite achieved improved conductivity after heating. The d.c. conductivities are comparable to those of many commercial inorganic or organic composites, and because of their attractive electrical properties, we suggest that these materials are promising for electronic field applications. [ABSTRACT FROM AUTHOR]

The development of sensitive breast cancer biomarker (CA 15-3) measurement techniques is of great significance for the early diagnosis and therapeutic monitoring of breast cancer worldwide. Herein, we have designed a split-type photoelectrochemical (PEC) immunoassay platform for the ultrasensitive determination of CA 15-3 using In2O3/ZnIn2S4 heterojunctions with high photovoltaic conversion performance as a photoactive substrate. Efficient photocurrent-responsive In2O3/ZnIn2S4 was formed by surface loading narrow-bandgap ZnIn2S4 on MOF-derived wide bandgap In2O3 nanomaterials. Subsequently, a sandwich immunoreaction was performed using an alkaline phosphatase (ALP)-labeled secondary antibody as a signaling indicator to produce large amounts of ascorbic acid by enzymatic biocatalysis. Since ascorbic acid is an excellent electron donor capable of promoting photogenerated electron separation in semiconductor materials, it enhances the anodic photocurrent of In2O3/ZnIn2S4-modified electrodes. Under the optimal catalyst loading and immunoreaction time, the In2O3/ZnIn2S4-based PEC immunoassay showed a good photocurrent response to CA 15-3 over a wide detection range from 1.0 mU mL-1 to 10000 mU mL-1 with a limit of detection of 0.45 mU mL-1. Owing to the excellent photocurrent response of In2O3/ZnIn2S4 to ascorbic acid and the split-type immunoassay protocol, the constructed PEC immunosensing platform has the advantages of high precision, anti-interference, and acceptable accuracy, and the results are equivalent to those of commercial enzyme-linked immunosorbent assay (ELISA) kits. [ABSTRACT FROM AUTHOR]

Semiconductor materials have become the primary photocatalysts for photocatalytic hydrogen production. However, the design and synthesis of effective photocatalytic materials with excellent electron/hole separation efficiency, fast charge transfer, and low carrier recombination rate still face great challenge. Herein, hollow p-n heterojunction MoS 2 @ZnIn 2 S 4 nanoboxes are synthesized for the first time by growing n-type ZnIn 2 S 4 (ZIS) two-dimensional nanosheets on the surface of p-type hollow MoS 2 nanoboxes (MSNBs), which exhibits obvious photocatalytic activity. Among them, 5% MSNBs@ZIS photocatalyst shows the highest hydrogen production efficiency of 22.25 mmol h-1 g-1, which is 7.3 times that of pure ZIS. The high photocatalytic hydrogen production efficiency of 5% MSNBs@ZIS can be attributed to the formation of hollow structure and p-n heterojunction, which can provide a large number of catalytic active sites, large surface area, and can effectively promote the separation of photogenerated carriers, respectively. Hollow p-n heterojunction MoS 2 @ZnIn 2 S 4 nanoboxes are synthesized for the first time by growing n-type ZnIn 2 S 4 two-dimensional nanosheets on the surface of p-type hollow MoS 2 nanoboxes, which exhibits obvious photocatalytic activity. Through characterization and theoretical calculations reveal that the enhanced photocatalytic activity of 5% MoS 2 @ZnIn 2 S 4 nanobox photocatalyst is due to the formation of hollow structure and p-n heterojunction, which can provide a large number of catalytic active sites, large surface area, and can effectively promote the separation of photogenerated carriers, respectively. [Display omitted] • The hollow p-n heterojunction MSNBs@ZIS nanocomposites were synthesized successfully. • The hydrogen evolution rate of MSNBs@ZIS photocatalyst is 7.3 times higher than that of pristine ZIS. • The high efficiency can be attributed to the formation of hollow structure and p-n heterojunction. [ABSTRACT FROM AUTHOR]

Based on density functional theory (DFT), the structural and physical properties of NaCaZ (Z = N, P, As) half-Heusler (HH) semiconductor materials have been studied under pressure up to 20 GPa. The ground state results show that the NaCaZ are chemically stable in α -phase structure and exhibit semiconducting behavior with an indirect bandgap. The optical parameters like the real and imaginary components of complex dielectric function, the absorption coefficient and refractive index are investigated and discussed. The obtained results show that NaCaZ have low value of reflectivity and high absorption coefficient in low ultraviolet and visible regions and exhibit small changes under pressure. Pressure-based elastic constants and their derivative parameters show that NaCaZ are mechanically stable and have brittle nature. Above 10 GPa, NaCaP and NaCaAs have ductile nature. The phonon dispersions calculations with pressure show that NaCaN and NaCaP are dynamically stable, in contrast, NaCaAs is dynamically unstable at ambient pressure. Above 10 GPa, the studied compounds are dynamically stable. The mechanically, dynamically stable with low reflectivity and high absorption coefficient in the low ultraviolet and visible regions make these materials more promising as absorbers of solar cells, optoelectronic and 2D applications. [ABSTRACT FROM AUTHOR]

High‐purity octafluoropropane (C3F8) electronic specialty gas is a key chemical raw material in semiconductor and integrated circuit manufacturing industry, while selective removal of hexafluoropropylene (C3F6) impurity for C3F8 purification is essential but a challenging task. Here we report a fluorinated cage‐like MOF Zn‐bzc‐CF3 (bzc=5‐(trifluoromethyl)‐1H‐pyrazole‐4‐carboxylic acid) for C3F6/C3F8 separation. The incorporation of −CF3 groups not only provides suitable pore aperture size for highly efficient size‐exclusive C3F6/C3F8 separation, but also creates hydrophobic microenvironments, endowing Zn‐bz‐CF3 high chemical stability. Remarkably, Zn‐bzc‐CF3 exhibits high C3F6 adsorption capacity while excluding C3F8, achieving ideal molecular‐sieving C3F6/C3F8 separation. Breakthrough experiments show that Zn‐bzc‐CF3 can efficiently separate C3F6/C3F8 mixture and high‐purity C3F8 (99.9 %) can be obtained. [ABSTRACT FROM AUTHOR]

Photodetectors are widely used in various fields, such as industrial manufacturing and military defense. Researchers have recently sought a photodetector that combines high polarization sensitivity and a robust optical response. As an anisotropic semiconductor material, SnS holds potential for photodetection across the visible light spectrum. This study employs first-principles density functional theory (DFT) along with the non-equilibrium Green's function (NEGF) method to theoretically investigate the optoelectronic properties of the SnS monolayer in two device orientations: Armchair and Zigzag. It is found that the maximum photocurrent values between the two orientations are small at zero bias voltage, and stable photocurrent can be obtained by adding bias voltage. We examine the maximum photocurrent variation under linearly polarized light irradiation within a small bias voltage range (0.1 to 1.0 V), found for the maximum photoresponse of monolayer SnS to be large and stable at photon energy of 2.4 and 3.2 eV, and analyze the underlying mechanism of photoresponse, employing energy band and density of state diagrams. Additionally, we have calculated the extinction ratio of the SnS monolayer, confirming its strong polarization sensitivity. Finally, by subjecting the device to biaxial strain, we significantly speculate to enhance its asymmetry, leading to a substantial increase in photocurrent at zero bias. A compressive strain of - 6% notably increases the photocurrent. These findings offer valuable theoretical insights for the design of SnS monolayers as photodetectors. [ABSTRACT FROM AUTHOR]

With the fast development and miniaturization of acoustic and electric smart devices, micro and nanoscale piezoelectric semiconductor materials are gradually being used to manufacture information communication, energy conversion, and nondestructive testing technologies. As the core components of the above piezoelectric semiconductor devices, homo- and hetero-junctions have an evident influence on the propagation performance of high-frequency and short-wavelength elastic waves inside the bulk piezoelectric semiconductor materials. Based on the Gurtin–Murdoch theory, a theoretical model of interface effect originating from homo- and hetero-junctions is established to investigate the propagation properties of Love waves in a piezoelectric semiconductor semi-infinite medium considering the electrical open circuit (insulation) and short circuit (metalized ground) surface boundary conditions and biasing electric fields. Four interface characteristic lengths are introduced to describe the electrical imperfect interface of homo- and hetero-junctions, which are legitimately confirmed through comparisons of the dispersion and attenuation curves of Love waves. The influence of homo- and hetero-junctions on the dispersion and attenuation characteristics of Love waves are elaborated in detail. Numerical results show that the interface characteristic lengths are independent of the electrical surface boundary conditions, acceptor and donor concentrations, thickness of the upper piezoelectric semiconductor layer, and biasing electric fields in the piezoelectric semiconductor semi-infinite medium. Moreover, the propagation characteristics of Love waves can be manipulated by changing the biasing electric field parallel to the homo- and hetero-junctions. Since the high-frequency and short-wavelength Love wave is an important class of surface acoustic waves propagating in micro- and nano-scale piezoelectric semiconductor materials, the establishment of mathematical models and the revelation of physical mechanisms are fundamental to the analysis and optimization of the above piezoelectric semiconductor devices. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) is a promising semiconductor material in the field of photocatalysis due to its excellent electronic and optical properties. Due to its wide bandgap, ZnO cannot absorb visible light, which limits its photocatalytic performance. The current research is mainly to reduce the bandgap of wurtzite ZnO by doping different atoms, so as to enhance its visible light absorption, but the effect is limited. Under the framework of first‐principles calculation, three alkaline earth metal elements, Be, Mg, and Ca, are selected to dope the low‐energy sites in the cavities of Zn12O12 cluster‐assembled material (SOD type) with single and double atoms, respectively (equivalent to the doping concentration of 8.3% and 16.7%) using a combination of geometric optimization and molecular dynamics, and a stable new semiconductor material with direct bandgap less than 1 eV is obtained, which has excellent light absorption properties in the visible region. In addition, the reason for the bandgap reduction of doped materials is revealed by analyzing the energy band structures and the density of states. This work provides a new idea for the development of new photocatalytic material based on ZnO. [ABSTRACT FROM AUTHOR]

Doping of semiconductor materials can significantly alter the characteristics of the intrinsic semiconductors. The titanium dioxide (TiO2) has been doped with a variety of dopants to yield enhanced optical, electronic, and mechanical properties. Such dopants in the original lattice of TiO2 produce defect sites with segregation and accumulation of ions on the grain boundaries. The segregation of ions results in the decreased conductivity of the TiO2. Aside from the ion segregation, the diffusion of ions into the TiO2 may subsequently alter the grain boundaries arrangement by either increasing or reducing the barrier height. The ability to tailor the crystalline arrangement is highly dependent on the nature of the dopant employed. Therefore, it is important to understand the roll of the dopants and control the doping process in order to modify the grain boundary and thus band gap structure of the doped TiO2. This article provides a comprehensive review of the TiO2 doping with four different types of dopants in view of their impact on optical, electronic, and mechanical properties in order to obtain optimized characteristics. Significant application of doped TiO2 as a photocatalyst and surge protector is briefly discussed on the basis of optical, electronic and mechanical properties. [ABSTRACT FROM AUTHOR]

The lack of suitable channel semiconductor materials has been a limiting factor in the development of tunneling field-effect transistor (TFET) architectures due to the stringent criteria of both air stability and excellent gate-tunable electronic properties. Here, we report the performance limits of sub-10-nm double-gated monolayer (ML) BiN TFETs by utilizing first-principles quantum-transport simulations. We find that ML BiN possesses an indirect bandgap of 0.8 eV and effective masses of 0.24m0 and 2.24m0 for electrons and holes, respectively. The n-type BiN TFETs exhibit better performance than the p-type ones, and the on-state current can well satisfy the requirements of the International Roadmap for Devices and Systems for both high-performance and low-power standards. Notably, we find that the BiN TFETs exhibit distinguished gate controllability with an ultra-low subthreshold swing below 60 mV/decade even with a small gate length of 6 nm, which is superior to the existing field-effect transistors, such as black phosphorus TFETs, GeSe TFETs, and BiN metal–oxide–semiconductor field-effect transistors. Furthermore, the BiN TFETs are endowed with the potential to realize high switching speed and low-power consumption applications because of their extremely short delay time and ultra-low power-delay product. Our results reveal that the ML BiN is a highly competitive channel material for the next-generation TFETs. [ABSTRACT FROM AUTHOR]

The sharp changes in optical and electrical properties in the VO2 metal–semiconductor phase transition are regarded as an on–off switch to regulate the photocatalytic performance of VO2@TiO2. As the switch is ON, the application of VO2 in the metal phase has doubled the photocatalytic performance of TiO2 in both rutile and anatase phases; as the switch is OFF, VO2 in the semiconducting phase has shrunk the photocatalytic performance of TiO2 by one-third. This innovative combination of thermochromism of VO2 and photocatalysis of TiO2 has effectively broadened the utilization of the two kinds of semiconductor materials. [ABSTRACT FROM AUTHOR]

Cellulose has recently been utilized as a green and eco-friendly substrate template for synthesizing semiconductor oxide materials. This paper introduces a novel and sustainable method for obtaining In 2 O 3 nano octahedrons, using cellulose nanofibers (CNF) as sacrificial templates. To demonstrate the importance and advantages of the CNF template, a parallel synthesis was conducted under the same conditions, but with no CNF. The as-prepared In 2 O 3 compounds were thoroughly characterized by XRD, SEM, and XPS techniques. The CNF template-assisted route resulted in an approximately 3000 % particle size reduction and a narrow distribution compared to the sample prepared with no CNF as a template. Notably, the sensing performance towards ozone (O 3) gas was also substantially enhanced in the CNF template-assisted sample and a significantly higher response (Rg/Ra = 42 @ 70 ppb O 3) was observed compared to the In 2 O 3 sample with no CNF (Rg/Ra = 3.5 @ 70 ppb O 3). Furthermore, sensors based on CNF-assisted In 2 O 3 octahedra synthesis showed greater selectivity towards O 3 than towards NO 2 , another oxidizing gas, and a relatively lower operation temperature (200 °C). The enhancement in gas sensing properties for O 3 detection was attributed mainly to the higher concentration of chemically adsorbed oxygen species and surface defects, such as oxygen vacancies, which were promoted by the reduction in the particle size and the removal of CNF, respectively. The sustainable and CNF template-assisted approach represents a promising result for environmentally-friendly synthesis and advanced gas sensing applications. [ABSTRACT FROM AUTHOR]

Transition metal-based perovskites have emerged as highly promising and economically advantageous semiconductor materials due to their exceptional performance in optoelectronics, photovoltaic, photocatalysis, and photoluminescence. In this study, we employed a microwave-assisted hydrothermal process to produce a Cu-doped NiMnO3 nanocomposite electrode material. The appearance of a peak corresponding to the (110) plane with a 2θ value of 36.6° confirmed the growth of the rhombohedral NiMnO3 crystal structure. The presence of metal–oxygen bonds in NiMnO3 was confirmed through FTIR spectra. XPS validates the chemical composition, providing additional support for the results obtained from XRD and FT-IR analyses. FE-SEM affirmed the anisotropic growth of small sphere-like structures that agglomerated to form broccoli-like shapes. Cu doping modified the band gap, reducing it from 2.2 to 1.7 eV and enhancing its photoluminescent (PL) activity by introducing defects. The increase in PL intensity (visible light luminescent intensity) can be attributed to a concurrent rise in complex defects and the rate of recombination of electron–hole pairs. Finally, the electrochemical activity demonstrated the pseudo-capacitor behavior of the synthesized material, with capacitance values increasing as the copper (Cu) content in the parent lattice increased. [ABSTRACT FROM AUTHOR]

Multiferroic van der Waals (vdW) heterostructures offer an exciting route toward the nanoelectronics and spintronics device technology. How to realize the mutual regulation between ferroelectric and magnetic materials has attracted extensive research. In this work, based on the density functional theory, we simulate a vdW multiferroic heterostructure based on the bipolar magnetic semiconductor material graphone and ferroelectric monolayer In2Te3 and further investigate its electronic properties. We find that direct contact between In2Te3 and graphone induces a transition in graphone from a ferromagnetic state to a non-magnetic state. Fortunately, the magnetic properties of graphone are preserved by using graphene as an intercalation layer, and the graphone monolayer changes from its original semiconductor to a half-metal in the graphone/graphene/In2Te3 vdW heterostructure for P↓ state. Furthermore, by adjusting the layer spacing of the heterostructure, the spin polarization states of graphone at the Fermi level (EF) are regulated between spin-up (S↑) and spin-down (S↓) with the reversal of ferroelectric polarization states. Our results not only provide a promising way to realize the half-metallicity in 2D magnetic materials but also computationally predict the ferroelectric control of the spin polarization state, which has great application potential in the next-generation nonvolatile electrically controlled spintronic devices. [ABSTRACT FROM AUTHOR]

The progressive reduction in feature size presents significant challenges such as crosstalk, heat dissipation, and high-power consumption, which impede the advancement of Moore's Law. To overcome the limitations of silicon materials, it is crucial to identify subsequent iterations of innovative semiconductor materials or alternative structures. The integration of two-dimensional (2D) materials and three-dimensional (3D) structures offers a promising platform for exploring novel photodetectors and alternative pathways toward "More than Moore" technologies. In this study, we present a comprehensive evaluation of the underlying mechanisms governing the formation of diverse 3D structures, along with their corresponding preparation methodologies. We focus our evaluation on the distinctive optical properties arising from the incorporation of a self-rolled-up 3D structure into 2D materials and heterojunctions photodetector. Finally, we address some of the challenges and outlook that persist in the development and application of 3D-structured photodetectors based on 2D materials. [ABSTRACT FROM AUTHOR]

Removal of organic pollutants from wastewater remains a significant challenge. Hence, we report a series of novel MOFs based BixTiy‐BTC photocatalysts synthesized by hydrothermal method for decontamination of 1,1‐Dimethylhydrazine (UDMH). The preparation parameters of MOFs were optimized, the best catalytic performance was achieved by adjusting the Bi/Ti molar ratio to 1 : 3, with Bi1Ti3‐BTC a photocurrent density of 0.35 mA/cm2 was reached. The morphology and composition of the materials were analyzed, titanium doping increased the specific surface area. Bi1Ti3‐BTC was loaded with magnetic nano‐Fe3O4, which prevented agglomeration of Bi1Ti3‐BTC and increased the specific surface area, thus improving photocatalytic activity. The band gap structure of the semiconductor materials was estimated by UV‐Vis and XPS valence band spectra, while the separation efficiency of photogenerated carriers was investigated by photocurrent density and PL (Photoluminescence) spectrum. The photocatalytic degradation rate of UDMH rapidly decreased after addition of EDTA, indicating that h+ was the main active species in the photocatalytic degradation process. The photocatalytic removal efficiency of UDMH with Bi1Ti3‐BTC/Fe3O4 at a concentration of 0.5 g/L reached 97.58 % after illumination for 180 min, and after 210 min near quantitative degradation was observed. [ABSTRACT FROM AUTHOR]

The energy level matching of perovskites was regarded as the prerequisite for achieving high photovoltaic performance. Graphitic carbon nitride (g-C3N4) is a two-dimensional polymer semiconductor material, which has good semiconductor properties, suitable electronic band structure and excellent physical and chemical stability, and is widely used in energy and materials science fields such as for photovoltaic conversion. Graphene oxide (GO) is a two-dimensional π-conjugated carbon atom sheet formed by sp2 hybrid bonds. Due to its unique electronic properties, g-C3N4 can be seamlessly spliced with the two-dimensional domains of GO through continuous π-conjugated bonds, which not only effectively modifies the electronic structure of g-C3N4 but also contributes to the unhindered separation and transfer of electrons and holes in the plane. Therefore, in this work, we effectively passivated film trap defects and significantly reduced non-radiative recombination by constructing GO/g-C3N4 heterostructures as an ultra-thin interface modification layer between the perovskite layer and the electron transport layer (ETL). As a result, the addition of a GO/g-C3N4 heterojunction modification layer facilitated achieving an improved power-conversion efficiency (PCE 20.50% to 22.08%), inhibited the recombination of carriers, and improved the mobility of carriers. An unpackaged device demonstrated excellent stability, maintaining more than 90% of the initial efficiency after over 1,000 hours of storage under ambient conditions. [ABSTRACT FROM AUTHOR]

This work focused on developing optical coatings for decorative applications that remain transparent in the radiofrequency range. To achieve this, a combination of dielectric material (silicon-aluminum nitride, SiAlNx) and low-electrical-conductivity semiconductor material (germanium) was utilized. Germanium plays a crucial role in providing absorption in the visible spectrum, facilitating the design of coatings with various aesthetic appearances, while allowing for control over their transmittance. The optical properties of thin germanium layers were thoroughly characterized and leveraged to create multilayer designs with diverse aesthetic features. Different multilayer structures were designed, fabricated, and optically characterized, resulting in coatings with metallic gray, black, or various colors in reflection, while retaining the ability to transmit visible light for illumination and signaling applications. Finally, the radiofrequency attenuation of the developed coatings was measured, revealing negligible attenuation; this is in stark contrast to the metallic coatings used for decorative purposes, which can attenuate by up to 30 dB. [ABSTRACT FROM AUTHOR]

The interest in the Spark Plasma Sintering (SPS) technique has continuously increased over the last few years. This article shows the possibility of the development of an SPS device used for material processing and synthesis in both scientific and industrial applications and aims to present manufacturing methods and the versatility of an SPS device, presenting examples of processing Arc-Melted- (half-Heusler, cobalt triantimonide) and Self-propagating High-temperature Synthesis (SHS)-synthesized semiconductor (bismuth telluride) materials. The SPS system functionality development is presented, the purpose of which was to broaden the knowledge of the nature of SPS processes. This approach enabled the precise design of material sintering processes and also contributed to increasing the repeatability and accuracy of sintering conditions. [ABSTRACT FROM AUTHOR]

Metal halide perovskite nanoplatelets (NPls) have recently joined a rich family of 2D semiconductor nanomaterials. Quantum and dielectric confinement in these nanostructures endow them with useful optical properties, which include, but are not limited to, high linear and nonlinear absorption coefficients, narrow and tunable emission bands, and high photoluminescence quantum yield. These characteristics render perovskite NPls promising for applications in lighting, photodetection, nonlinear optics, and photocatalysis. Doping is a universal approach for tuning optical and electronic properties of semiconductor materials, and the B‐site doping of perovskite NPls allows the further improvement and adjustment on demand of the above‐mentioned optical properties and may result in the appearance of fundamentally new behavior through embedding optically active dopants. In this mini‐review, the basic knowledge about perovskite NPls is shortly summarized in terms of their colloidal synthesis, and then the B‐site doping of perovskite NPls is considered in terms of the existing approaches (in situ and post‐synthetic doping) and its effect on the optical characteristics (doping with self‐emitting ions such as Mn2+ and rare‐earth elements; consequences for the nonlinear optical response). [ABSTRACT FROM AUTHOR]

Organic semiconductor materials are considered to be promising photocatalysts due to their excellent light absorption by chromophores, easy molecular structure tuning, and solution‐processable properties. In particular, donor‐acceptor (D‐A) type organic photocatalytic materials synthesized by introducing D and A units intra‐ or intermolecularly, have made great progress in photocatalytic studies. More and more studies have demonstrated that the D‐A type organic photocatalytic materials combine effective carrier separation, tunable bandgap, and sensitive optoelectronic response, and are considered to be an effective strategy for enhancing light absorption, improving exciton dissociation, and optimizing carrier transport. This review provides a thorough overview of D‐A strategies aimed at optimizing the photocatalytic performance of organic semiconductors. Initially, essential methods for modifying organic photocatalytic materials, such as interface engineering, crystal engineering, and interaction modulation, are briefly discussed. Subsequently, the review delves into various organic photocatalytic materials based on intramolecular and intermolecular D‐A interactions, encompassing small molecules, conjugated polymers, crystalline polymers, supramolecules, and organic heterojunctions. Meanwhile, the energy band structures, exciton dynamics, and redox‐active sites of D‐A type organic photocatalytic materials under different bonding modes are discussed. Finally, the review highlights the advanced applications of organic photocatalystsand outlines prospective challenges and opportunities. [ABSTRACT FROM AUTHOR]

Semiconductor photocatalysis, as a safe and environmentally friendly technology, has drawn a lot of attention due to its potential to address issues with energy and the environment. Recently, different semiconductors have been designed and modified in order to obtain efficient photocatalysts. Here, semiconductor photocatalytic materials and the reaction fundamentals of semiconductor photocatalysis are briefly introduced. Six methods have been introduced to improve the photocatalytic activity of semiconductors, which are morphology and crystal modification, doping induction, plasmonic metal nanoparticles deposition, heterojunctions construction with other semiconductor materials, dye sensitization, and organic modification. Besides, the challenges and potential for developing semiconductor photocatalytic materials in the future are highlighted. It is hoped to help preparing semiconductors with better photocatalytic performance. • Outlining six methods for enhancing the performance of photocatalysts. • Discussion about the mechanism of photocatalysis. • Different methods have good photodegradation efficiency for different organic pollutants. • Introducing various methods of doping and the different types of heterojunctions. [ABSTRACT FROM AUTHOR]

Future alternative and promising energy sources involve photoelectrochemical (PEC) devices that can convert sunlight and abundant resources such as water and CO2 into chemical fuels and value-added products. However, identifying suitable photoabsorber semiconductor materials that fulfill all the stringent requirements of photoelectrodes in PEC devices remains a significant challenge. A key factor for tailoring and optimizing existing and novel photoabsorbers is understanding the processes occurring at the semiconductor/liquid electrolyte interface under working conditions. This perspective focuses on the application of operando Raman spectroscopy (RS) in synergy with (photo)electrochemical techniques. Despite being a relatively new field of application, when applied to photoelectrochemistry, operando RS offers insights into the evolution of photoelectrode structure (i.e. phase purity and degree of crystallinity) and surface defects under working conditions. The challenges associated with operando RS for (photo)electrochemical applications, including the low quantum efficiency of inelastic scattering and fluorescence, and possible mitigation strategies are discussed. Furthermore, practical aspects such as sample/reactor geometry requirements and the surrounding environment of the photoelectrode sample during operando RS under PEC conditions are reviewed. We demonstrate that operando RS can be used to perform product analysis of solar-driven biomass reforming reactions, showing the approach's limitations and discussing possible solutions to overcome them. This work concludes with a discussion on the current state of operando RS of semiconducting photoelectrodes and devices for photoelectrochemistry. We show a new methodology for performing operando RS with illumination resembling AM 1.5 conditions and with time resolution spanning from tens to hundreds of milliseconds, suitable timescales for real-time monitoring of chemical reactions and degradation mechanisms occurring at the photoelectrode under investigation. [ABSTRACT FROM AUTHOR]

In recent years, the remarkable properties and potential applications of III-nitride (III-N) semiconductors have sparked a significant interest in the field of microelectromechanical systems (MEMS). Traditionally, III-N MEMS are fabricated through a process involving the epitaxial growth of III-N epilayers on a silicon substrate followed by etching the handle wafer to generate free-standing structures. In this study, we explore the potential of a relatively simple approach based on the two-dimensional (2D) material-based liftoff and transfer to fabricate III-N mechanical resonators. The methodology involves van der Waals epitaxy of III-N layers on 2D hexagonal-boron nitride (h-BN), which leverages the weak van der Waals adhesion between h-BN layers to lift off and transfer these layers from their original growth substrate to an alternative host substrate. The employed method is demonstrated by fabricating 600 nm thick GaN/AlGaN and 2.5 μm thick h-BN micro-resonators onto pre-patterned cavities etched in silicon substrates. These devices are characterized using laser Doppler vibrometry, enabling the observation of well-defined modes of vibration and resonant frequencies. Furthermore, finite element method simulations are performed to gain insights into the experimental observations and the mechanical properties of the transferred layers. This approach could be extended to transfer high-quality III-N MEMS devices onto various host substrates, including flexible substrates, and could be used to assess the mechanical properties of emerging III-N semiconductor materials. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV)‐sensitive semiconductors play a key role in converting UV light into electric signals in a UV photodetector. Two‐dimensional (2D) oxide perovskite, as a kind of green and stable semiconductor materials, exhibits excellent UV detection capabilities. However, the non‐dense nanosheet thin film induces alternative shunts in vertical‐structured devices results in high ohmic leakage currents. Large number of oxygen vacancies in 2D oxide perovskite leads to the adsorption / desorption process of oxygen molecules that slows down the device's response speed. Therefore, an inorganic–organic heterojunction that effectively fills up the pinholes in nanosheet films, effectively suppressing the dark current of the device by 100 000 times are designed. Meanwhile, the construction of inorganic–organic heterojunctions can accelerate the charge carriers' transporting process, resulting in a fast rise / decay response time of 0.7 ms / 8.5 ms. Moreover, the inorganic–organic heterojunction endows the device with excellent self‐powered performance, presenting a high responsivity of 60 mA W−1. This photodetector demonstrates application potential in a UV communication system with a detection angle of 30 degrees and a close‐range communication of 1.2 m. [ABSTRACT FROM AUTHOR]

This article reviews the mechanisms and latest research progress of structural regulation enhanced photocatalysis and enhanced photocatalysis through external fields synergistic structural regulation, and the advantages and disadvantages of each external field enhanced photocatalysis are discussed・ Photocatalysis is a technique that converts solar energy directly into chemical energy. It has great potential in environmental governance and energy crisis resolution. The rapid recombination of photoelectron-hole pairs greatly limits the photocatalytic efficiency of photocatalysts・ Through structural regulation, such as element doping, noble metal loading, construction of heterojunction structure, can greatly improve the efficiency of photocatalysis, but their application still has strong limitations. In recent years, the application of external fields (mechanical stress, microwave, temperature gradient, electric field, magnetic field, etc ・)in photocatalytic reactions has significantly improved the efficiency of photocatalysis and broadened the application range of photocatalysis・ The prospects and challenges of enhanced photocatalysis through external fields synergistic structural regulation are discussed. [ABSTRACT FROM AUTHOR]

This study presents the synthesis and characterization of 3D ZnO@MoS2 nanocomposites, demonstrating their superior performance in photoelectrochemical applications. Employing a combination of hydrothermal and solvothermal methods, the research focuses on creating heterostructures with optimized interfacial characteristics. The ZnO@MoS2 composites show a substantial increase in photocurrent density (1.02 mA/cm²), compared to ZnO nanorods (0.32 mA/cm²), underlining enhanced charge separation efficiency. In electrocatalytic hydrogen evolution, the heterostructures exhibit a lower onset potential (-175 mV vs RHE) and reduced Tafel slope (51 mV/dec), indicating improved catalytic activity over MoS2 nanosheets. Additionally, the composites demonstrate a significant increase in electrochemical capacitance (398 F/g at 10 mV/s), suggesting potential applications in energy storage. These results highlight the efficacy of ZnO@MoS2 nanocomposites in enhancing solar energy conversion and storage, providing insights into the development of next-generation semiconductor materials. [ABSTRACT FROM AUTHOR]