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Thermal gradient‐driven fluid motion, also known as thermal convection, is a common and significant phenomenon in nature. The utilization of localized thermal gradients to induce convection has emerged as a competitive approach in microfluidic chips. This technique enables the long‐distance transportation of substances under the influence of low‐power lasers. In this paper, an innovative optofluidic micro‐platform is presented that possesses a simple structure, easy operation, and excellent expandability. A UV nanosecond laser is utilized to create a high photothermal conversion region (HPCR) within the carbon nanotube‐doped PDMS substrate. Subsequently, the HPCR is subjected to irradiation for generating localized thermal gradients in the microfluidic chip. This resulted in Rayleigh–Bernard convection formation and facilitated long‐range transport and control of fluids and particles. Under low‐power laser irradiation, particles can be transported at speeds up to 0.18 mm s−1. In addition, the optofluidic platform shows significant potential for a range of functionalities, including fluid mixing and material sorting. The methodology described here allows for the rapid integration of new functionalities into existing chips while maintaining cost effectiveness and efficiency. This technique holds great promise for expanding the use of microfluidic devices in diverse fields, including chemistry, health sciences, materials science, and biomedicine. [ABSTRACT FROM AUTHOR]

Spectroscopic analysis of trivalent praseodymium (Pr+3) and neodymium (Nd+3) ions have received very much interest and reveals good fluorescence efficiency in visible and near IR (NIR) region. Cadmium sulfide (CdS) nanomaterial sample doped with Pr+3 and Nd+3 ions are synthesized at room temperature by simple chemical precipitation method. The synthesized sample has been characterized by powder X‐ray diffraction studies, scanning electron microscopy, transmission electron microscopy, and energy dispersive X‐ray spectra. Absorption spectra of CdS:Nd3+ and CdS:Pr3+ nanoparticles have been recorded at room temperature. Various parameters such as interplanar spacing, micro strain, dislocation density, distortion parameter, and particle size of nanomaterial are computed. TEM and XRD analysis reveal the spherical structure of the CdS:Nd3+ and CdS:Pr3+ nanoparticles in the prepared samples. Energy interaction parameters of the CdS:Nd3+ and CdS:Pr3+ nanoparticles are computed using UV‐visible absorption spectrum. Actually, CdS nanoparticle amplifies the luminescence intensity of Pr+3, Nd+3 ions by up conversion processes. So energy transfer can be observed from CdS nanoparticles doped with Pr+3, Nd+3 ions. Therefore, the use of pump sources and diode lasers in the UV range can be used to excite these samples to work as lasers. CdS:Nd3+ and CdS:Pr3+ nanoparticles find potential application as a window material for hetero‐junction solar cell, light emitting diodes (LED), biological sensors, address decoders, gas detectors, opto‐electronic devices, etc. CdS nanomaterials are also used as pigment in paints and in engineered plastic due to their good thermal stability. [ABSTRACT FROM AUTHOR]

Rationale: Characterization of Regolith And Trace Economic Resources (CRATER), an Orbitrap™‐based laser desorption mass spectrometry instrument designed to conduct high‐precision, spatially resolved analyses of planetary materials, is capable of answering outstanding science questions about the Moon's formation and the subsequent processes that have modified its (sub)surface. Methods: Here, we describe the baseline design of the CRATER flight model, which requires <20 000 cm3 volume, <10 kg mass, and <60 W peak power. The analytical capabilities and performance metrics of a prototype that meets the full functionality of the flight model are demonstrated. Results: The instrument comprises a high‐power, solid‐state, pulsed ultraviolet (213 nm) laser source to ablate the surface of the lunar sample, a custom ion optical interface to accelerate and collimate the ions produced at the ablation site, and an Orbitrap mass analyzer capable of discriminating competing isobars via ultrahigh mass resolution and high mass accuracy. The CRATER instrument can measure elemental and isotopic abundances and characterize the organic content of lunar surface samples, as well as identify economically valuable resources for future exploration. Conclusion: An engineering test unit of the flight model is currently in development to serve as a pathfinder for near‐term mission opportunities. [ABSTRACT FROM AUTHOR]

We utilize a novel, high-power, tunable, continuous wave (CW) deep UV laser to measure resonance Raman spectra of phenolate solutions with high signalto-noise ratios (SNR). In UV resonance Raman (UVRR), increased coupling of the excitation light with a chromophore can transfer molecules into excited states that cause increased heating and photochemistry. Deep UV lasers have traditionally utilized high peak powers to enable efficient single-pass nonlinear conversion from visible into near infrared light. Nonlinear phenomena such as the formation of transient radical species, Raman saturation, thermal heating, and dielectric breakdown can introduce extraneous light sources that can complicate the interpretation of the Raman spectrum. Dielectric breakdown can increase the baseline, increase noise, and sometimes saturate the detector, preventing Raman detection. Spontaneous Raman scattering intensities should scale linearly with the excitation light intensity. However, this linear behavior does not always occur with pulsed laser excitation. This occurs because stimulated Raman scattering can cause a superlinear intensity response, or transient absorption can cause sublinear intensity responses. CW laser excitation excites samples with electric fields that are much lower than typical pulsed laser excitation. This eliminates the nonlinear responses. The geometry of our new CW laser enables high gain in the harmonic generation cavities that achieve high harmonic generation efficiencies. Average power in the deep UV is >30 mW for wavelengths as short as 206 nm. In the work here, we demonstrate that CW excitation is ideal for resonance Raman measurements in general to reduce spectral complexity. [ABSTRACT FROM AUTHOR]

The effect of terahertz (THz) radiation has been studied in medicine. However, there is a lack of scientific information regarding its possible mutagenicity. Therefore, the present study aimed to assess the mutagenicity of 1.6 THz laser irradiation. The Ames test was conducted using five bacterial tester strains. The bacteria were subjected to (i) 1.6 THz laser irradiation at 3.8 mW/cm2 for 60 min using a tabletop THz pulse laser system, (ii) ultraviolet irradiation, (iii) treatment with positive control chemicals (positive control) or (iv) treatment with the solvent used in the positive control (negative control). After treatment, the bacterial suspensions were cultured on minimal glucose agar to determine the number of revertant colonies. In addition, the comet assay was performed using fibroblasts (V79) to assess possible DNA damage caused by the THz laser irradiation. The Ames test demonstrated that the THz laser irradiation did not increase the number of revertant colonies compared to that in the negative control group, whereas the ultraviolet irradiation and positive control treatment increased the number of revertant colonies. Thus, 1.6 THz laser irradiation is unlikely to be mutagenic. The comet assay additionally suggests that the THz laser irradiation unlikely induce cellular DNA damage. [ABSTRACT FROM AUTHOR]

Preparing viable single cells is critical for conducting single‐cell RNA sequencing (scRNA‐seq) because the presence of ambient RNA from dead or damaged cells can interfere with data analysis. Here, we developed a method for isolating viable single cells from adult planarian bodies using fluorescence‐activated cell sorting (FACS). This method was then applied to both adult pluripotent stem cells (aPSCs) and differentiating/differentiated cells. Initially, we employed a violet instead of ultraviolet (UV) laser to excite Hoechst 33342 to reduce cellular damage. After optimization of cell staining conditions and FACS compensation, we generated FACS profiles similar to those created using a previous method that employed a UV laser. Despite successfully obtaining high‐quality RNA sequencing data for aPSCs, non‐aPSCs produced low‐quality RNA reads (i.e., <60% of cells possessing barcoding mRNAs). Subsequently, we identified an effective FACS gating condition that excluded low‐quality cells and tissue debris without staining. This non‐staining isolation strategy not only reduced post‐dissociation time but also enabled high‐quality scRNA‐seq results for all cell types (i.e., >80%). Taken together, these findings imply that the non‐staining FACS strategy may be beneficial for isolating viable cells not only from planarians but also from other organisms and tissues for scRNA‐seq studies. [ABSTRACT FROM AUTHOR]

It is well known that nickel‐based catalysts have high electrocatalytic activity for the 5‐hydroxymethylfurfural oxidation reaction (HMFOR), and NiOOH is the main active component. However, the price of nickel and the catalyst's lifetime still need to be solved. In this work, NiOOH containing oxygen vacancies is formed on the surface of Ni alloy by UV laser (1J85‐laser). X‐ray absorption fine structure (XAFS) analyses indicate an interaction between Mo and Ni, which affects the coordination environment of Ni with oxygen. The chemical valence of Ni is between 0 and 2, indicating the generation of oxygen vacancies. Density functional theory (DFT) suggests that Mo can increase the defect energy and form more oxygen vacancies. In situ Raman electrochemical spectroscopy shows that Mo can promote the formation of NiOOH, thus enhancing the HMFOR activity. The 1J85‐laser electrode shows a longer electrocatalytic lifetime than Ni‐laser. After 15 cycles, the conversion of HMF is 95.92%. [ABSTRACT FROM AUTHOR]

The metal stop laser drilling of GaN‐on‐GaN devices is demonstrated using a UV sub‐nanosecond laser as a light source. By monitoring the Bremsstrahlung emission at the drilling point, metal stops with a precision higher than 1 μm are realized for vias with a depth of 100 μm. From in situ laser‐induced breakdown spectroscopy measurements, it is shown that endpoint detection is realized with high signal‐to‐noise ratio owing to the difference in the emission process between the strongly excited semiconductor and the metal. Herein, a through‐substrate electrode with a resistance of less than 5 mΩ on GaN‐on‐GaN high‐electron‐mobility transistor (HEMT) wafers is demonstrated. The fabrication of through‐substrate electrodes by this technique provides a simple process that does not require lithography or other complex processes. This process is expected to be useful in the fabrication of future GaN‐on‐GaN devices, including very thin GaN‐on‐GaN HEMTs. [ABSTRACT FROM AUTHOR]

Rationale: Boron isotopes are a powerful tool for pH reconstruction in marine carbonates and as a tracer for fluid–mineral interaction in geochemistry. Microanalytical approaches based on laser ablation multi‐collector inductively coupled plasma mass spectrometry (LA‐MC‐ICP‐MS) often suffer from effects induced by the sample matrix. In this study, we investigate matrix‐independent analyses of B isotopic ratios and apply this technique to cold‐water corals. Methods: We employ a customized 193 nm femtosecond laser ablation system (Solstice, Spectra‐Physics) coupled to a MC‐ICP‐MS system (Nu Plasma II, Nu Instruments) equipped with electron multipliers for in situ measurements of B isotopic ratios (11B/10B) at the micrometric scale. We analyzed various reference materials of silicate and carbonate matrices using non‐matrix matched calibration without employing any correction. This approach was then applied to investigate defined increments in coral samples from a Chilean fjord. Results: We obtained accurate B isotopic ratios with a reproducibility of ±0.9‰ (2 SD) for various reference materials including silicate glasses (GOR132‐G, StHs6/80‐G, ATHO‐G and NIST SRM 612), clay (IAEA‐B‐8) and carbonate (JCp‐1) using the silicate glass NIST SRM 610 as calibration standard, which shows that neither laser‐induced nor ICP‐related matrix effects are detectable. The application to cold‐water corals (Desmophyllum dianthus) reveals minor intra‐skeleton variations in δ11B with average values between 23.01‰ and 25.86‰. Conclusions: Our instrumental set‐up provides accurate and precise B isotopic ratios independently of the sample matrix at the micrometric scale. This approach opens a wide field of application in geochemistry, including pH reconstruction in biogenic carbonates and deciphering processes related to fluid–mineral interaction. [ABSTRACT FROM AUTHOR]

Arrays of stretchable and transparent electronic sensors realize next‐generation skin‐conformable wearables and soft robotic skins, which require a high‐resolution patternable stretchable conductor. However, the difficulty of simultaneously engineering desirable material properties (i.e., conductivity, stretchability, and patternability) has limited the development of such stretchable electronic materials. Herein, a high‐resolution patternable, stretchable, and transparent conducting polymer by decoupled engineering of the material properties is shown. The high conductivity of the conducting polymer is achieved by rationally designing an ionic additive. The high stretchability is realized by matching the mechanical properties of the conducting polymer to the substrate. The developed conducting polymer is then patterned in a resolution less than 10 µm by nanosecond UV laser ablation, which enables the feasible demonstration of stretchable and transparent sensor arrays for touch and strain. The findings in this work will accelerate the development of high‐density stretchable sensor arrays and stretchable semiconductor devices. [ABSTRACT FROM AUTHOR]

Neuromorphic perceptual system (NPS) is inspired by the interaction between organisms and environment, which has boosted many emerging fields like human–machine interfaces and bionic robots. Laser‐induced graphene (LIG) can be a fast, low cost, and accurate patterning technology toward a flexible and biological plausible NPS. While, to unleash the full potential of LIG, thorny issues like low endurance and limited stretchability should be addressed. Herein, high‐performance ultraviolet LIG (UV‐LIG) based sensors and electrodes are introduced for building flexible artificial sensory neuron (ASN). The UV‐LIG can be fabricated with a fine linewidth of ≈75 µm and a high conductivity of 3900 ± 150 S cm−1, which facilitates the demonstration of LIG toolbox, containing bending sensors, flexible heaters, etc. The transferred LIG electrodes retain good conducting property (only ≈12.7% increment in resistance) and enable large stretchability (up to 150% strain), outperforming most of the LIG‐based strain sensors. As a proof‐of‐concept, an artificial sensory neuron that is able to mimic the strain perception of somatosensory system is realized based on the integration of LIG‐based functional components and an InGaZnO (Indium‐Gallium‐Zinc Oxide, IGZO)‐based synaptic transistor. This work can provide an efficient patterning methodology as well as essential components for neuromorphic perceptual systems. [ABSTRACT FROM AUTHOR]

Optical bound states in the continuum (BICs), realizing substantial suppression of out‐of‐plane radiative losses, have been utilized to realize strong light confinement and optical modes with high quality‐factor (Q). Lasing actions with narrow linewidths based on optical BIC modes have been demonstrated in the near‐infrared and the visible ranges, but BIC‐based lasers in the ultraviolet (UV) region have not been reported. As light sources possessing wavelengths at the UV scale are essential in various fields, the strategy to design compact UV lasers based on high‐Q modes and directional emissions is highly desirable. Here, the first BIC‐based laser in the UV region is demonstrated by designing a 1D periodic resist structure on top of a GaN film. Using the symmetric‐protected BIC mode, the fabricated laser is having a directional single‐mode lasing emission with a small full‐width at half‐maximum of 0.10 nm and beam divergence of 1.5°. The lasing action is observed with a periodic structure area corresponding to a structure side length as small as 8 µm. Moreover, the wavelength control of the UV lasing is achieved by varying the period and temperature. This work provides strategies to design UV lasers having a small footprint together with narrow‐linewidth and out‐of‐plane emissions. [ABSTRACT FROM AUTHOR]

Raman spectra obtained by UV laser excitation above 260 nm are contaminated by spectrally overlapping UV‐excited fluorescence. Here, we demonstrate a picosecond UV Kerr‐gated Raman spectroscopy setup to suppress the fluorescence in Raman spectra excited by 280 nm laser pulses. Specifically, we use a model sample that consists of acetonitrile contaminated by a small amount of toluene for generating UV‐excited fluorescence. We were able to acquire a Raman spectrum of acetonitrile by suppressing the UV‐excited fluorescence of toluene by the action of a 1‐mm thick fused silica‐based UV Kerr gate operated by 1030 nm, ~1 ps gating pulses. These results also indicate the challenges that must be overcome in the future for realizing UV‐fluorescence‐free UV resonance Raman (UVRR) spectroscopy studies of molecules exhibiting electronic resonances around 280 nm using laser excitation wavelengths right at or close to this resonance. [ABSTRACT FROM AUTHOR]

Interactions of DNA with structural proteins such as histones, regulatory proteins and enzymes play a crucial role in major cellular processes such as transcription, replication and repair. The in vivo mapping and characterization of the binding sites of the involved biomolecules are of primary importance for a better understanding of genomic deployment that is implicated in tissue and developmental stage‐specific gene expression regulation. The most powerful and commonly used approach to date is immunoprecipitation of chemically cross‐linked chromatin (XChIP) coupled with sequencing analysis (ChIP‐seq). While the resolution and the sensitivity of the high‐throughput sequencing techniques have been constantly improved, little progress has been achieved in the cross‐linking step. Because of its low efficiency, the use of the conventional UVC lamps remains very limited while the formaldehyde method was established as the "gold standard" cross‐linking agent. Efficient biphotonic cross‐linking of directly interacting nucleic acid–protein complexes by a single short UV laser pulse has been introduced as an innovative technique for overcoming limitations of conventionally used chemical and photochemical approaches. In this survey, the main available methods including the laser approach are critically reviewed for their ability to generate DNA–protein cross‐links in vitro model systems and cells. [ABSTRACT FROM AUTHOR]

In the past 15 years, ambient ionization techniques have witnessed a significant incursion into the field of mass spectrometry imaging, demonstrating their ability to provide complementary information to matrix‐assisted laser desorption ionization. Matrix‐assisted laser desorption electrospray ionization is one such technique that has evolved since its first demonstrations with ultraviolet lasers coupled to Fourier transform‐ion cyclotron resonance mass spectrometers to extensive use with infrared lasers coupled to orbitrap‐based mass spectrometers. Concurrently, there have been transformative developments of this imaging platform due to the high level of control the principal group has retained over the laser technology, data acquisition software (RastirX), instrument communication, and image processing software (MSiReader). This review will discuss the developments of MALDESI since its first laboratory demonstration in 2005 to the most recent advances in 2021. [ABSTRACT FROM AUTHOR]

Lead‐free double halide perovskites stand out as a promising material for constructing stable and environmental‐friendly photodetectors (PDs) because of the excellent stability and nontoxicity. However, the performance (e.g., detectivity and response speed) of lead‐free double halide perovskites based PDs is still low. Herein, highly sensitive, stable, and fast‐response Cs2AgBiBr6 perovskite PDs are presented by synergistic engineering of doping optimization of Na+/Ce3+ and integrating with Ag nanoparticles (NPs). Compared to pristine Cs2AgBiBr6, Cs2AgBiBr6:Na+,Ce3+ film is endowed with higher crystallization quality and better stability after Na+,Ce3+ codoping, toward the reduced defect density, the improved charge mobility. Meanwhile, a significantly enhanced charge extraction and transport in Cs2AgBiBr6:Na+,Ce3+/Ag NPs hybrid film is achieved by further integrating with Ag NPs. Finally, Cs2AgBiBr6:Na+,Ce3+/Ag NPs hybrid film‐based PDs are developed, delivering high detectivity of 1.34 × 1012 Jones@460 nm and 1.18 × 1012 Jones@370 nm, which is the relatively high in lead‐free double halide perovskites PDs and exceeds the most results of the previous reports in the ultraviolet and visible range. The devices also show outstanding stability and fast‐response time (395 ns). This work opens up a novel frontier for developing lead‐free perovskite PDs. [ABSTRACT FROM AUTHOR]

Topological materials have great potential in lossless electronic transportation. Bi2Te3 as three‐dimensional (3D) topological insulator is predicted to exhibit many amazing electromagnetic characteristics, which are widely studied all over the world. However, current research available on Bi2Te3 materials is not adequate, and a comprehensive understanding of its properties is necessary. In this work, near‐field plasmon imaging based on Bi2Te3 nanostructures and the kinetic energy spectra of emitted electrons from Bi2Te3 film by using photoemission electron microscope instruments is studied. Under UV laser excitation of 273 nm, the electrons can be excited from the trap states in bandgap, which provides a feasible idea for observing the trap energy levels of Bi2Te3 materials. Moreover, the imaging applications of nanostructures in Bi2Te3 film based on their polarization‐dependence and wavelength‐dependence properties are also demonstrated, providing a more degrees of freedom for imaging, and can realize multidimensional and multi‐multiplexing imaging technology of topological materials. This work provides a novel method to enrich the Bi2Te3 film properties from the view of near‐field plasmon imaging and kinetic energy distribution, paving the way for realizing practical applications of topological materials. [ABSTRACT FROM AUTHOR]

Machining process is generally required for cutting composite material of structural components prior to final assembly in aerospace industry. This study aimed to investigate surface quality and mechanical behavior of open‐hole composite laminates following different machining processes including abrasive waterjet cutting, high power fiber laser machining, conventional drilling and ultraviolet laser machining. Hole quality was quantified for further understanding the correlation between surface damage and mechanical behavior. Experimental results demonstrated that the hole geometrical accuracy and mechanical property were highly dependent on the machining methods. Digital image correlation technique was implemented to capture the strain distribution and strain evolution around open holes during tensile loading. Machining methods exhibited significant impact on εyy, εxx, and εxy strain levels around hole edges, while limited influence on strain distribution patterns. εyy and εxx concentrated in the regions consisting of fibers perpendicular to and along the loading direction respectively, and shear strain εxy featured with X shape around hole edge. [ABSTRACT FROM AUTHOR]

Electrospun nonwovens have great potential for biomedical applications. They can be used, for example, to mimic the structure of the extracellular matrix of biological tissue. In this work, it is demonstrated that the surface properties of nanofiber nonwovens made of biocompatible and very slowly biodegrading polyamide can be modified by UV picosecond laser processing. Basically, the nanofiber structure is only slightly changed by the corresponding laser process. Significant laser‐induced material change occurs only along narrow lines determined by the scanning process. The newly formed surface structures resemble a bulk surface. It is shown that the growth of mammalian chondrocyte cells (SW1353) is initially more effective on the laser‐processed surface. Cell growth occurs preferably along the laser‐generated lines. After several days of cell growth, an extended layer of cells is formed over the laser‐modified and unmodified surface sections. Thus, laser‐based surface modification provides another tool to affect cell proliferation on polyamide nanofiber nonwovens. [ABSTRACT FROM AUTHOR]

Short‐wave infrared (SWIR) information is critical for material analysis, imaging sensing, and other fields. To acquire SWIR spectrum with compact devices, strategies for reconstructive microspectrometer have emerged, such as photonic crystal and quantum dot filter. However, the current SWIR microspectrometer needs many filters with insufficient resolution. In this work, the authors develop a SWIR chip‐spectrometer based on Fabry–Perot microcavities array which can be fabricated by using fast and low‐cost UV laser direct‐writing grayscale lithography. The ultra‐compact chip‐spectrometer can work in a very wide range from 900 to 1700 nm with only 20 detector pixels and a reconstruction algorithm. The spectral resolution achieves 2 nm by 50 pixels set and 5 nm by 20 pixels set at SWIR range, which is 3 times higher, with 3.9 times less units number, than for recently reported SWIR quantum dot spectrometers. To the best of our knowledge, this is a minimum high‐resolution SWIR InGaAs detector based chip‐spectrometer which can work in the whole SWIR band with only 20 detector pixels. It has great potential for applications in smart‐phone or other miniature portable spectrometers. [ABSTRACT FROM AUTHOR]

Cover Photograph: Fabrication of superhydrophobic glass with high processing efficiency and low production cost has always been a challenge. In https://doi.org/10.1111/ijag.16643, surface functionalization combining UV nanosecond laser texturing and silicone oil‐assisted heat treatment was used to create both superhydrophilic and superhydrophobic surfaces (upper images). The lower images are SEM micrographs of the untreated glass and the same material with laser texturing at various line spacings.. [Extracted from the article]

Ultraviolet (UV) lasers with dynamic wavelength‐tunability and high monochromaticity are crucial in a multitude of practical applications yet still remarkable challenges. Here, we show wide wavelength‐tuning of single‐mode UV lasing based on lanthanide‐doped upconversion nanoparticles (UCNPs). The rationally designed Yb3+/Er3+/Tm3+/Gd3+/Ce3+ co‐doped multilayer UCNPs, which exhibits a broad gain spectrum with the full width of half maximum of around 57 nm in the UV regime, are developed. More importantly, by taking advantages of a diffraction grating as the tuning component, stable single‐mode emission can be achieved in the UCNPs‐based external‐cavity‐extended Fabry–Pérot laser at room temperature. Specifically, the lasing threshold is around 137 µJ cm–2, which is two orders of magnitude lower than that in the previously reported articles. Precise wavelength‐tuning from 310 to 363 nm can be realized by adjusting the Littrow angle. This achievement highlights a portable alternative to continuously wideband‐tunable UV lasers and opens up new opportunities for constructing compact solid‐state UV photon sources. [ABSTRACT FROM AUTHOR]

The CO2 methanation is an important component of the "power to gas" strategy, and the Ru‐Al2O3 catalyst is considered to be a state‐of‐the‐art catalyst for this reaction. Conventional Ru‐Al2O3 is prepared by wet impregnation. Due to weak interactions between Ru and the Al2O3, construction of a controllable interface between the metal and the substrate is still challenging. In this work, a UV pulse laser is used to controllably construct ultra‐small Ru nanoparticles on defects‐rich Al2O3‐x‐L in situ grown on Al foil (Ru‐Al2O3‐x‐L) for effective photothermal CO2 methanation. The catkin‐like fluff Al2O3‐x‐L efficiently traps light to ensure the light adsorption of Ru‐Al2O3‐x‐L. The defects in Al2O3‐x‐L efficiently anchors Ru. A Strong‐Metal‐Support‐Interaction (SMSI) effect is constructed between the ultra‐small Ru nanoparticles and the Al2O3‐x‐L. The Ru‐Al2O3‐x‐L exhibits remarkable photothermal catalytic performance (CH4 yield of 12.35 mol gRu−1 h−1) in the closed batch system. Then an innovative flow reactor is established based on the one‐piece Ru‐Al2O3‐x‐L microchannel catalyst. Thanks to local pressure on the edge of the microchannels, the CH4 yield is further enhanced to 14.04 mol gRu−1 h−1. Finally, an outdoor setup demonstrates the feasibility of photothermal CO2 methanation (CH4 yield of 18.00 mmol min−1). This work provides novel perspectives for the construction of multi‐level micro/nanostructures integrated catalysts for photothermal CO2 methanation. [ABSTRACT FROM AUTHOR]

Cesium lead halide perovskite nanocrystals (NCs) have gained enormous attention as promising light‐emitting and light‐converting materials. Most of their applications require embedding NCs in various matrices, which is a challenging task due to their low stability, especially in the case of red‐emitting CsPbI3 NCs. In this work, a new approach is proposed allowing the formation of red‐emitting perovskite NCs by anion exchange induced directly inside a solid polymer matrix using green‐emitting CsPbBr3 NCs as templates and iodododecane as an iodine source. Moreover, a simple and efficient route to photo‐assisted termination of the anion exchange reaction in the polymer composite after reaching desired optical properties is demonstrated. The findings allow the authors to pattern a thin composite film with an ultrashort UV laser resulting in a selective generation of green‐ and red‐emitting features with a 15 µm resolution. [ABSTRACT FROM AUTHOR]

Due to low penetration ability of ultraviolet (UV) light, UV‐induced free radical reactions of polymers are limited to the preparation of thin‐layer materials such as coatings and inks. Although upconversion (UC) nanomaterials that can be excited by near‐infrared (NIR) light and emit UV light which is used to achieve polymerization or curing of monomers or prepolymers, low quantum efficiency and high excitation threshold limit their applications. Here, triplet‐triplet annihilation up‐conversion luminescent (TTA‐UCL) chromophores of platinum (II) octaethylporphyrin (PtOEP) and 9,10‐diphenylanthracene (DPA) are used to realize TTA‐UCL‐assisted photoinitiated polymerization of butyl acrylate (BA) and ethoxylated trimethylolpropane triacrylate (ETPTA) as well as photo curing of polyurethane acrylates (PUA) using visible light at 520 nm. The effects of chromophores concentrations and incident light power density on double‐bond conversion rate are investigated. The results show that a mediate TTA‐UCL chromophore concentration of 0.02% is beneficial for polymerization of ETPTA‐co‐BA with thickness of 25 mm within 15 min. Satisfied adhesion of colored plastic substrates using PUA prepolymers can be achieved after irradiation for 30 s when chromophore concentration of 0.1% is used. TTA‐UCL assisted photoinitiated reactions show great potential in engineering aspects including quick repair of leaking tubes and photocuring of adhesives underwater. [ABSTRACT FROM AUTHOR]

Laser‐induced graphene (LIG) produced by irradiation of paper (paper‐LIG)holds substantial promise for flexible devices. This article presents paper‐LIG humidity and temperature sensors fabricated by single‐step irradiation of common filter paper with a pulsed UV laser (355 nm). The influence of the process parameters on the conversion of cellulose fibers into LIG is discussed based on the resulting morphology, structure, conductivity, and chemical composition, revealing a distinct barrier to transformation and a propagation behavior not seen under CO2 laser irradiation. The obtained material is constituted by a porous, electrically conductive network of fibers. The paper‐LIG relative humidity (RH) and temperature sensors with sensitivities of up to 1.3 × 10−3%RH−1 and ‐ 2.8 × 10−3 °C−1, respectively, are examined in terms of their linearity, reproducibility, and response time. A detailed discussion on the response mechanism is presented in the context of literature, pointing towards the absorption of water molecules in the interlayer spacing of graphene as the main reason for the increase in resistance with RH. Additionally, a contribution from variable range hopping along the ab plane of graphene at high RH is suggested. These results demonstrate the potential of paper‐LIG for low‐cost, sustainable, and environmentally friendly sensing. [ABSTRACT FROM AUTHOR]

The central processes driving biological phenomena are based on the conduction of ions and electrons in biomaterials, implying the possibility of achieving a fully biomaterial‐based electronic skin. However, finding the appropriate biomaterials for electronic skins is still challenging. Here, a photoresponsive, self‐healable, and biomaterial‐based optoelectronic skin (OE‐skin) fabricated with melanin nanoparticles and silk protein is proposed and the electronic properties and their mechanisms in the artificially generated OE‐skin are reported. Not only does silk protein hydrogel provide a transparent and skin‐compatible platform for use as OE‐skin but it also provides the appropriate environment for melanin to demonstrate high electrical conductivity. The OE‐skin can be considered a p‐type semiconducting material showing high conductivity of up to 6 mS cm−1 in addition to a 40% enhancement in the conductivity by green laser and ultraviolet light emitting diode illuminations. Additionally, the OE‐skin autonomously heals itself from multiple cuts, allowing the restoration of its electrical properties. These material properties enable applications for strain‐sensors, humidity sensors, and ultraviolet light sensors, as well as image pixels to convert light‐lettering into electrical signals. The proposed fully biomaterial‐based OE material platform offers a new way for next‐generation electronic skins to achieve a seamless interface with the human body. [ABSTRACT FROM AUTHOR]

With the arrival of the "von Neumann bottleneck," neuromorphic systems are receiving a lot of attention from scholars as an innovative technology by mimicking the massive parallelism and low‐power operation of the human brain. Herein, a floating‐gate‐like device constructed by the InSe/hBN/O2‐hBN van der Waals heterostructure, where the defective O2‐hBN plays the central role to trap charges, is proposed. This well‐designed device is proved to realize the synaptic functions under UV laser irradiation, such as short‐term plasticity (STP), long‐term plasticity (LTP), paired‐pulse facilitation (PPF), and long‐term potentiation/long‐term depression (LTP/LTD). Especially, the synaptic weight of excitatory postsynaptic current (EPSC) reaches as high as 104%, it reaches the highest standard of this kind of device in recent years, and remains above 300% synaptic weight after 200 s, thus successfully imitating the LTP in biological synapses. The key factors of LTP/LTD curves are overall excellent and can be optimized with input pulses: nonlinearity value can reach 3.32/2.35, and Gmax/Gmin above 10 is achieved. The InSe floating‐gate‐like device with O2‐hBN layer provides an alternative for better and more practical synaptic performances in the field of neuromorphic architectures based on 2D materials. [ABSTRACT FROM AUTHOR]

The properties of graphene oxide foils were modified by excimer laser irradiation at different fluences and times. The irradiations were performed in air and in vacuum using a pulsed UV laser operating at 248‐nm wavelength and 23‐ns pulse duration. Measurements of ablation yield, microscope surface morphology and Raman spectroscopy were performed. The residual surface shows a significant oxygen reduction due to the removing of functional oxygen groups, a thickness reduction due to the removal of graphene layers depending on the used laser shots and a presence of defects in the graphene sheets as evident by the Raman spectroscopy investigation. [ABSTRACT FROM AUTHOR]

Micrometric foils of graphene oxide are prepared in the laboratory starting from water dispersed solution of graphene oxide at low concentration. Measurements on five physical properties have been performed in the foils of graphene oxide and reduced graphene oxide. The reduction is obtained thermally, using IR and UV laser irradiations and MeV helium ion beam irradiations at different fluence. The parameters such as the atomic composition, the mass density, the surface roughness, the wetting ability, and the electrical conductivity are investigated. This last parameter assumes different values for the pristine graphene oxide foils and for the reduced ones. Comparison of experimental measurements with the literature data and the results and discussion are presented. [ABSTRACT FROM AUTHOR]

Background: Hyperpigmentation is a common concern of patients in dermatology clinics. Although there are many treatment options, lasers are considered a promising therapy for various hyperpigmentary conditions. Objectives: This study aims to evaluate the efficacy of alexandrite 755‐nm picosecond and neodymium‐doped yttrium aluminum garnet (Nd:YAG) 1064‐nm picosecond lasers for the treatment of ultraviolet B (UVB)‐induced hyperpigmentation in Asians. Materials and Methods: A randomized, single‐blinded study was conducted. UVB‐induced hyperpigmentation was performed in three spots by narrowband UVB. After 2 weeks, these three spots were allocated into 755‐treated, 1064‐treated, and control sites. Patients received weekly laser treatments for five sessions. Follow‐ups were scheduled at 1 and 2 months after the last session. Results: Twenty patients attended the study. Overall, 755‐nm and 1064‐nm picosecond lasers showed a significant improvement in the mean lightness index (L*) compared to the control site, which started at Day 49 and Day 77, respectively. The mean L* of the 755‐nm‐treated site was also higher than that of the 1064‐nm–treated site at Day 105 (p ≤ 0.001). Initially, the mean L*, physician's visual analog scale (VAS), and patient satisfaction with the 1064‐nm picosecond laser were better than those with the 755‐nm picosecond laser. Nevertheless, an inversion of the mean L* and VAS was noted at Day 49, whereas the mean patient satisfaction was noted at Day 77. In the subgroup analysis, a 755‐nm picosecond laser effectively treated Fitzpatrick skin types (FPTs) III and IV. However, the mean L* of the 1064‐nm picosecond laser was not significantly different from that of the control for FPT4. Conclusion: The alexandrite 755‐nm picosecond and Nd:YAG 1064‐nm picosecond lasers appear to be effective and safe modalities for treating UVB‐induced hyperpigmentation. With the setting employed in this study, the outcome after the 755‐nm picosecond laser treatment seemed superior to that of the 1064‐nm picosecond laser treatment, especially for FPT4. [ABSTRACT FROM AUTHOR]

Stereolithographic additive manufacturing (STL‐AM) has been developed to create practical components with functional geometries. Nanoparticles are mechanically dispersed into photosensitive resins, and the resulting mixed paste is thinly spread on a flat substrate. One‐dimensional (1D) raster lines were cured via ultraviolet laser scanning. Two‐dimensional (2D) cross‐sections are formed by adjacent joining. Three‐dimensional (3D) solid structures are fabricated via lamination bonding. The composite precursors were dewaxed and sintered under optimized heat treatment conditions. Computer‐aided design, manufacture, and evaluation (CAD/CAM/CAE) processes of acoustic devices with rigid alumina structures will be progressively reviewed. Cylindrical cavities were divided into self‐similar volumes as harmonic instruments to perform overtone sounds. Spherical cavities were connected with steric junctions as noise suppressors to exhibit absorption bands. Qualitative improvements in social and industrial environments by using stereolithographic technologies are discussed and practically demonstrated. [ABSTRACT FROM AUTHOR]

A one‐step laser lift‐off (LLO) for patterned gallium nitride (GaN) film and GaN‐based light‐emitting diode (LED) device is achieved using 355 nm picosecond laser irradiation in this research. The laser fluence required for separation is 0.09–0.13 J cm−2, which is much lower than that for the currently reported LLO methods. The separated GaN film is intact with only 0.04 GPa of residual stress. The ultra‐smooth separated surface with root mean square roughness of only 5.2 nm is attributed to the interconnection of microcrack‐free flat cavities formed by the combination of high photon energy‐induced intrinsic absorption and subsequent plasma generation. The flat cavity with a depth‐to‐width ratio of 1:4000 limits the delamination region to a few nanometers at the GaN/sapphire interface. GaN‐based LED is transferred with perfect electroluminescence (EL) by the strategy. The stable EL spectral peak positions and intensity independent of the bending state prove that the presented low‐energy ultrafast LLO technique ensured the flexibility of the separated LED device without affecting the performance. This research provides a promising strategy to achieve the LLO of GaN devices with low energy consumption, high controllability, and high efficiency, which is significant for the industrial fabrication of flexible GaN‐based electronics. [ABSTRACT FROM AUTHOR]

A one‐step laser lift‐off (LLO) for patterned gallium nitride (GaN) film and GaN‐based light‐emitting diode (LED) device is achieved using 355 nm picosecond laser irradiation in this research. The laser fluence required for separation is 0.09–0.13 J cm−2, which is much lower than that for the currently reported LLO methods. The separated GaN film is intact with only 0.04 GPa of residual stress. The ultra‐smooth separated surface with root mean square roughness of only 5.2 nm is attributed to the interconnection of microcrack‐free flat cavities formed by the combination of high photon energy‐induced intrinsic absorption and subsequent plasma generation. The flat cavity with a depth‐to‐width ratio of 1:4000 limits the delamination region to a few nanometers at the GaN/sapphire interface. GaN‐based LED is transferred with perfect electroluminescence (EL) by the strategy. The stable EL spectral peak positions and intensity independent of the bending state prove that the presented low‐energy ultrafast LLO technique ensured the flexibility of the separated LED device without affecting the performance. This research provides a promising strategy to achieve the LLO of GaN devices with low energy consumption, high controllability, and high efficiency, which is significant for the industrial fabrication of flexible GaN‐based electronics. [ABSTRACT FROM AUTHOR]

In view of their excellent luminescence properties, nanocrystalline metal halide perovskites have diverse optoelectronic applications, including those related to anticounterfeiting. However, high‐quality optical anticounterfeiting typically requires multiple encryptions relying on several optical modes to ensure information security. Herein, an efficient anticounterfeiting strategy based on dual optical encryption is realized by combining up‐ and downconversion luminescence in a nanocomposite with NaYF4 : Er3+,Yb3+ as core and a CsMnCl3 as shell. The emission color of this nanocomposite depends on the penetration depth of incident radiation and can be changed by varying the excitation source (980 nm laser or UV light) to produce different luminescent patterns. This feature allows one to effectively improve the anticounterfeiting index and fabricate professional anticounterfeiting materials. [ABSTRACT FROM AUTHOR]

In view of their excellent luminescence properties, nanocrystalline metal halide perovskites have diverse optoelectronic applications, including those related to anticounterfeiting. However, high‐quality optical anticounterfeiting typically requires multiple encryptions relying on several optical modes to ensure information security. Herein, an efficient anticounterfeiting strategy based on dual optical encryption is realized by combining up‐ and downconversion luminescence in a nanocomposite with NaYF4 : Er3+,Yb3+ as core and a CsMnCl3 as shell. The emission color of this nanocomposite depends on the penetration depth of incident radiation and can be changed by varying the excitation source (980 nm laser or UV light) to produce different luminescent patterns. This feature allows one to effectively improve the anticounterfeiting index and fabricate professional anticounterfeiting materials. [ABSTRACT FROM AUTHOR]

While native SAD phasing is a promising method for next‐generation macromolecular crystallography, it requires the collection of high‐quality diffraction data using long‐wavelength X‐rays. The crystal itself and the noncrystalline medium around the crystal can cause background noise during long‐wavelength X‐ray data collection, hampering native SAD phasing. Optimizing the crystal size and shape or removing noncrystalline sample portions have thus been considered to be effective means of improving the data quality. A crystal‐processing machine that uses a deep‐UV laser has been developed. The machine utilizes the pulsed UV laser soft ablation (PULSA) technique, which generates less heat than methods using infrared or visible lasers. Since protein crystals are sensitive to heat damage, PULSA is an appropriate method to process them. Integration of a high‐speed Galvano scanner and a high‐precision goniometer enables protein crystals to be shaped precisely and efficiently. Application of this crystal‐processing machine to a long‐wavelength X‐ray diffraction experiment significantly improved the diffraction data quality and thereby increased the success rate in experimental phasing using anomalous diffraction from atoms. [ABSTRACT FROM AUTHOR]

It is a great technical challenge to precisely polish diamond substrates due to their extremely high hardness, especially for micro‐optics fabrication. Here, a simple laser polishing process is demonstrated for the optical quality surface finish of chemical vapor deposition diamond using a 355 nm nanosecond laser. Raman spectroscopy and surface profile analyses reveal that the laser polishing is an ablation‐based process that consists of laser graphitization and the subsequent laser ablation of the graphitized layer. An optimized strategy is proposed to realize the high‐quality polishing by combining the ablation effect and defocusing laser irradiation. The polishing strategy can effectively reduce the peak‐to‐valley height difference of a rough surface and automatically enables the laser fluence at a low level close to the ablation threshold. Laser polishing at such critical laser fluence can greatly avoid harmful effects caused by high laser fluence and achieve precision materials' removal while maintaining optical surface quality. The approach is capable of delivering an average roughness Ra down to 8.02 nm and a high transmittance up to 80% of mechanically polished diamond in the visible spectrum. High optical performances make it possible to directly fabricate micro‐optical components on diamond substrates using this novel laser polishing approach. [ABSTRACT FROM AUTHOR]

Herein, aluminum gallium nitride (AlGaN)/AlN double‐heterostructure (DH) laser at 287 nm with a lasing threshold of 530 kW cm−2 is shown. The laser structure is grown on the AlN‐on‐sapphire template by molecular beam epitaxy. This lasing threshold is drastically reduced compared with the previously reported AlGaN DH lasers at 297 nm with a threshold of around 1 MW cm−2. The detailed studies indicate that this improvement is mainly attributed to the control of defect formation largely due to the increased growth temperature of the AlGaN active layer. This is consistent with the improved internal quantum efficiency at low excitations. Moreover, the control of Al vacancy related point defects is clearly demonstrated by the absence of defect emission in the visible band. [ABSTRACT FROM AUTHOR]

To date, it is still a challenge to acquire carbon nanomaterials with ultraviolet (UV) emission due to the trapping of excited carriers by defect states and surface groups. Herein, a pulsed laser ablation (PLA) method without any post‐treatments is developed to prepare carbon nanodots (CNDs). The cores of the resulting CNDs are graphitic carbon with negligible defects, whereas the surfaces are passivated by simple oxygen‐related groups, which is demonstrated by high‐resolution transmission electron microscope (HRTEM) image, X‐ray diffraction (XRD) pattern, and Raman spectra. Thus, the trapping of excited carriers by defect states and surface groups is substantially suppressed. As a consequence, the CNDs exhibit inherent UV emission of carbon nanostructures. The excitation‐independent UV emission peak contains three sub‐bands at 305, 325, and 335 nm. This work develops an approach for the preparation of UV‐emissive CNDs, which expands the applications of CNDs to UV‐related areas. [ABSTRACT FROM AUTHOR]

In this work, FT‐IR absorbance spectra of genomic DNAs isolated from four strains of Escherichia coli (A, B, C and D) and two strains of Salmonella (E and F), respectively, have been analyzed in both untreated and UV femtosecond laser pulses irradiated samples, to investigate their screening characteristics and their structural radiotolerance at 256 nm. Spectroscopic band assignments and structural aspects are discussed in the 600–1800 cm−1 and 3000–4000 cm−1 spectral ranges. DNA structural changes at the level of nucleic acids backbone, sugar, PO2− group, nitrogenous base ring and deoxycytidine (C2=O2) have been observed. Consequently, modifications in DNA conformations have been found. Bacterial strain dependent femtosecond laser pulses irradiation effects on DNA structure were observed. Based on FT‐IR biomarkers novel early diagnosis and screening tools for routine use in health care and life sciences can be developed. Furthermore, cancer research could benefit from ultra‐fast lasers technology. Besides, analyzing the interaction mechanisms of DNA with femtosecond laser pulses is highly appreciated for understanding the pathways of irradiation damaged DNA response in living cells. [ABSTRACT FROM AUTHOR]

Over the past decades, the aluminum gallium nitride (AlGaN) alloy system has received wide interest for the development of semiconductor deep ultraviolet (DUV) lasers due to its direct, tunable, and ultrawide bandgap energies (3.4–6.2 eV). The progress, nonetheless, has been remained slow, which is ascribed to a few major challenges, including large dislocation and defect densities, difficulty in obtaining p‐type high‐Al‐content AlGaN layers with a sufficient p‐type conduction, the large electric polarization fields, and the unfavorable optical polarization. In recent years, with AlGaN alloys grown by molecular beam epitaxy (MBE), including both thin films and nanowire structures, remarkable advancements have been made, such as highly conductive p‐type high‐Al‐content AlGaN epilayers with resistivities as low as 0.7 Ω cm and DUV lasing down to 239 nm with nanowire structures under a direct current injection. Herein, the recent progress on the DUV lasers by the MBE‐grown AlGaN is reviewed. The challenges and prospects of the MBE‐grown AlGaN for DUV lasers are also discussed. [ABSTRACT FROM AUTHOR]

The near‐band‐edge emission of Sb2Se3 microcrystals is studied in detail under high photoluminescence excitation density using a pulsed UV laser (λ = 266 nm, pulse width 0.6 ns). Based on the peak energy positions and the excitation power density and temperature dependencies (T = 3–110 K) of the photoluminescence spectra, the emission is interpreted as a recombination of two pairs (A and B) of free excitons and biexcitons appearing because of valence band splitting. The magnitude of the valence band splitting due to the crystal field (Δcr = 20–22 meV) is estimated in the Brillouin zone center. At T = 3 K, the A and B biexciton emission at 1.302 and 1.322 eV, respectively, and the A and B free exciton emission at 1.311 and 1.333 eV, respectively, are observed. The binding energy of A and B biexcitons is 9 and 11 meV, respectively, and the binding energy of A free exciton is 6 meV. The activation energy of thermal quenching for all observed peaks is 20 meV. [ABSTRACT FROM AUTHOR]

Pyrrolidinium based poly(ionic liquids) (PIL) are successfully obtained and characterized. Special attention is paid to the detailed characterization of the polymer products to determine their molecular-mass characteristics and to establish the composition-property relationship when selecting polymer electrolytes suitable for electrochemical tests. Characterization is performed using: chromatographic methods-combined gel permeation chromatography (GPC) with triple detection-refractometry, UV and laser light scattering; spectroscopy methods-Fourier transform infrared (FTIR), proton (1H) NMR spectroscopy; thermogravimetric analysis (TGA) and TGA/gas chromatography (GC)/mass selective detection (MSD). Supercapacitors based on commercial activated carbon, with electrolyte containing PIL dissolved in dimethylformamide (DMF) have been developed and preliminary charge/discharge galvanostatic tests in a two-electrode supercapacitor cell as well as an assessment of electrodes material and its stability in the polymeric ionic electrolyte were conducted. The PIL supercapacitor demonstrates stable capacitance characteristics and is promising for further studies in this direction. [ABSTRACT FROM AUTHOR]

Nano/microfabrication experiments on the surface of silicon solar cell are performed by ultraviolet femtosecond laser in the fluence range from 0.10 to 0.70 J/cm2. The surface morphology change of sample was observed by a laser scanning microscopy and a scanning electron microscope. The crystallinity of surface irradiated by laser pulses was evaluated by Raman spectroscopy. The ablation threshold for silicon was estimated to be 0.10 J/cm2. We successfully produced nano‐structures on the surface of silicon solar cell maintaining single‐crystalline with the irradiation at the laser fluence of 0.10 J/cm2. [ABSTRACT FROM AUTHOR]

Summary: Future of UV Lasertechnology in industrial PLD processes The success formula for any thin film technology on the production floor is bridging the gap between precisely depositing a functional thin film and at the same time achieving industrial processing rates. Fortunately, the pulsed laser deposition method has come of age thanks to output power and stability advances in UV excimer laser technology and has become a proven and industrial grade thin film deposition method. [ABSTRACT FROM AUTHOR]

A tolerance analysis approach based on interval arithmetic (IA) is proposed for heterogeneous three‐dimensional (3D) printed patch antennas. Four key parameters—patch length, width, substrate thickness, and material properties—are considered that can introduce errors in the analysis results. Investigating the comprehensive effect of these parameters on resonant frequency and the E/H pattern of the patch is difficult and time‐consuming when classical numerical simulations are employed. Thus, in this work, the four parameters are modeled as interval variables, and the equations between error and resonant frequency and the E/H pattern are derived using IA. Then, for the given tolerances (error intervals), the corresponding resonant frequency interval and E/H pattern interval are calculated using the proposed approach and compared with HFSS simulation results. Some samples of the patch antenna are fabricated via a self‐developed heterogeneous 3D printer, which employs ink injection and laser sintering to fabricate the patch and the microstrip; furthermore, ultraviolet (UV) resin injection and curing are used to fabricate the substrate. The transmission performance of the samples is evaluated by comparing simulation and measurement results to verify the effectiveness of the proposed IA‐based approach. [ABSTRACT FROM AUTHOR]

Zirconia is a dental material that shows excellent biocompatibility and high strength in clinical applications. This study aims to evaluate the effects of ultrafast laser applications. The surface nanostructures were classified into three groups. Group 1 was generated using the burst mode, with three different distances between dots: 52 µm (Group 1a), 104 µm (Group 1b), and 156 µm (Group 1c). Group 2 was processed using the scanning mode configuration, with a set of parallel lines. Group 3 was also processed using this scanning configuration creating a set of square‐shaped patterning. Group 4 was the control group. After the surface treatments, a pair of zirconia specimens was bonded end to end with resin cement. Flexural bond strength (FBS) test was applied in a universal test machine. Multiple comparisons were performed using a one‐way analysis of variance and the Tukey's HSD test. All the samples that were treated with the laser showed higher FBS values than the untreated surface. Using the burst mode, preformed circular‐shaped surface on an angle of 900 at 52 µm distance (Group 1a) showed the highest FBS values among all groups (p <.05). Groups 2 and 3 had significantly higher values than 1b and 1c. [ABSTRACT FROM AUTHOR]

Deep ultraviolet (UV) photodetectors have wide applications both in civil and military fields. Many materials have been explored to realize deep UV photodetection. Amorphous gallium oxide (a‐GaOx), as a member of transparent amorphous oxide semiconductors (TAOSs), has attracted a great deal of attention due to its ultrawide bandgap and scalable synthesis at room temperature. Plenty of researches have been focused on this topic in recent years. Herein, the latest progresses in the preparation methods of a‐GaOx using radio‐frequency sputtering, pulsed laser deposition, atomic layer deposition, and other deposition techniques are summarized. Dependence of the stoichiometry, crystallinity, optical, electrical, and morphological properties on different preparation parameters and doping/alloying elements is tentatively discussed, as well as those deep UV photodetectors based on a‐GaOx and related thin films. Finally, a short summary with further possible investigations is provided for a better understanding and development of a‐GaOx materials and photodetectors. [ABSTRACT FROM AUTHOR]