Light Materials Research Articles

Flood fragility and vulnerability functions for residential buildings in the Province of Leyte, Philippines

AbstractThe Philippines experiences frequent flooding, but, despite expansive tools for risk reduction, there remain gaps in understanding generalised relationships between flood events and damage to residential structures for regions outside the nation's capital. This gap has limited the ability to model flood risk and damage without robust functions to link hazards and housing vulnerability. This research draws on 394 household surveys to empirically derive a suite of flood fragility and vulnerability functions for residential structures in the Province of Leyte for light material, elevated light material and masonry structures. The results showed that masonry construction was more resilient to floods compared to light material counterparts. Elevated light material structures also exhibited lower damages at low inundations but tend to fail abruptly at flood depths greater than 3 m. By empirically deriving flood damage functions, the findings contribute to a more localised approach to quantifying housing vulnerability and risk that can be used for catastrophe and risk modelling, with applications for government agencies, the insurance industry and disaster risk researchers. This research lays the foundation for future flood risk mapping with growing significance under climate change.

Lembar Kerja Peserta Didik Berdasarkan Model Pembelajaran Generatif untuk Materi Gelombang Cahaya Kelas XI SMA

This research aims to develop LKPD based on a generative learning model on light wave material for class XI SMA that is valid and practical. The generative learning model was chosen because it is able to encourage students to actively build their understanding through interaction, reflection and discussion. This model has proven effective in improving critical thinking and problem-solving skills in physics learning. The developed worksheet is designed following the syntax of the generative learning model: orientation, cognitive conflict, disclosure, construct, application, and reflection, to support in-depth learning and link theory with real application. This research uses the Research and Development (R&D) method with the 4D development model (define, design, develop, disseminate). The define stage includes needs analysis and problem identification. At the design stage, the LKPD was designed by taking into account the content, structure, and aesthetic components. The development stage involves validity testing by experts, well as practicality testing by teachers and students. The dissemination stage is planned for wider application. The results showed that this LKPD has a very high level of validity with a validation index value of 0.94 in the content aspect and 0.86 in the structure aspect, which means that this LKPD meets the eligibility standards of the Merdeka curriculum. The practicality test shows that the LKPD is very practical with a teacher assessment score of 95% and a student assessment of 87%, so it is feasible to use it in the real field because it has been declared valid and practical.

Tensile, flexural and fatigue response of lightweight pumice-reinforced magnesium composite: Experimentation followed by an analytical modelling

Abstract Featherweight material to sustain mountainous loads is an extreme contrast. Still, in reality, the automobile and aerospace industries seek very light materials with high specific strength to survive in global competition. This study offers a timely answer to the problems faced by those sectors. Through the use of a stir-assisted squeeze casting method, the current investigation aims to generate a lightweight magnesium composite that is reinforced with porous low-density pumice particles at weight percentages of 5, 10, and 15 per cent. An examination of the density indicates that there is a downward tendency in conjunction with the growing reinforcement. In comparison to the magnesium alloy in its natural state, the Pumice 15 coupon achieves a tensile strength increment of 47%, flexural strength increment of 35% and a 10-times increment in service cycle at fatigue increase. The micromechanics model is implemented to justify the strengthening process in terms of the adhesion between the filler matrix and the interface shear strength. The property plots that were drafted provide evidence that the suggested material is lightweight while exhibiting a significant amount of strength in tensile, flexural and fatigue. Post-fracture surface morphology analysis exhibits distinct tensile, flexural and fatigue patterns.

Polarimetric 3D integral imaging profilometry under degraded environmental conditions

We propose polarimetric three-dimensional (3D) integral imaging profilometry and investigate its performance under degraded environmental conditions in terms of the accuracy of object depth acquisition. Integral imaging based profilometry provides depth information by capturing and utilizing multiple perspectives of the observed object. However, the performance of depth map generation may degrade due to light condition, partial occlusions, and object surface material. To improve the accuracy of depth estimation in these conditions, we propose to use polarimetric profilometry. Our experiments indicate that the proposed approach may result in more accurate depth estimation under degraded environmental conditions. We measure a number of metrics to evaluate the performance of the proposed polarimetric profilometry methods for generating the depth map under degraded conditions. Experimental results are presented to evaluate the robustness of the proposed method under degraded environment conditions and compare its performance with conventional integral imaging. To the best of our knowledge, this is the first report on polarimetric 3D integral imaging profilometry, and its performance under degraded environments.

Solution Processed Bilayer Metal Halide White Light Emitting Diodes.

Metal halide perovskites and perovskite-related organic metal halide hybrids (OMHHs) have recently emerged as a new class of luminescent materials for light emitting diodes (LEDs), owing to their unique and remarkable properties, including near-unity photoluminescence quantum efficiencies, highly tunable emission colors, and low temperature solution processing. While substantial progress has been made in developing monochromatic LEDs with electroluminescence across blue, green, red, and near-infrared regions, achieving highly efficient and stable white electroluminescence from a single LED remains a challenging and under-explored area. Here, a facile approach to generating white electroluminescence is reported by combining narrow sky-blue emission from metal halide perovskites and broadband orange/red emission from zero-dimensional (0D) OMHHs. For the proof of concept, utilizing TPPcarz+ passivated two-dimensional (2D) CsPbBr3 nanoplatelets (NPLs) as sky blue emitter and 0D TPPcarzSbBr4 as orange/red emitter (TPPcarz+ = triphenyl (9-phenyl-9H-carbazol-3-yl) phosphonium), white LEDs (WLEDs) with a solution processed bilayer structure have been fabricated to exhibit a peak external quantum efficiency (EQE) of 4.8% and luminance of 1507 cd m-2 at the Commission Internationale de L'Eclairage (CIE) coordinate of (0.32, 0.35). This work opens a new pathway for creating highly efficient and stable WLEDs using metal halide perovskites and related materials.

2D sheets of MoSe2 for waveguide based second harmonic generation

Two-dimensional transition metal dichalcogenides show a strong second-order nonlinear response, which can only be exploited if the interaction between light and 2D material is maximized as it happens in waveguiding structures. Such an approach also allows the addition of a second order nonlinear response to linear integrated optics components by just placing a sheet of transition metal dichalcogenides material on top. Here, we analyze the second harmonic generation in MoSe2 sheets combined with silicon nitride ridge and thin-film waveguides for both modal phase matching and quasi-phase-matching. The calculated second harmonic generation efficiency is comparable with that in lithium niobate waveguides and can further be enhanced by increasing the number of MoSe2 layers on top of the waveguides. This also holds true for flux correlated photons generated by spontaneous parametric down conversion as we show by quantitative analysis.

White Light Emission in Europium‐Doped Inorganic Perovskite Single Matrix

AbstractThe realization of stable single‐component white light emission in metal halide perovskites is still challenging due to the fast halide ion migration and narrow luminescence bands. In this work, all‐inorganic single CsPbClxBr3−x perovskite microplates with stable red‐blue‐green triple color light emission are prepared by introducing europium ions Eu3+ as dopants. Eu doping effectively suppresses ion migration and enables two spatially separated halide phases with stable dual‐wavelength emissions. Furthermore, the incorporation of Eu3+ compensates for the absence of red‐light emission, thereby yielding a superior white emission with exceptional quality. The color rendering index of triple‐color‐emitting perovskites can be tuned successfully by controlling the halogen ratios, and the optimal microplate achieved a Commissions Internationale de l’Eclairage (CIE) coordinates of (0.32, 0.32). The results present a new enlightenment for the preparation of low‐cost single‐component white light materials.

A hole-selective hybrid TiO2 layer for stable and low-cost photoanodes in solar water oxidation

The use of conductive and corrosion-resistant protective layers represents a key strategy for improving the durability of light absorber materials in photoelectrochemical water splitting. For high performance photoanodes such as Si, GaAs, and GaP, amorphous TiO2 protective overlayers, deposited by atomic layer deposition, are conductive for holes via a defect band in the TiO2. However, when coated on simply prepared, low-cost photoanodes such as metal oxides, no charge transfer is observed through amorphous TiO2. Here, we report a hybrid polyethyleneimine/TiO2 layer that facilitates hole transfer from model oxides BiVO4 and Fe2O3, enabling access to a broader scope of available materials for practical water oxidation. A thin polyethyleneimine layer between the light absorber and the hybrid polyethyleneimine/TiO2 acts as a hole-selective interface, improving the optoelectronic properties of the photoanode devices. These polyethyleneimine/TiO2 modified photoanodes exhibit high photostability for solar water oxidation over 400 h.

Controllable Multi-Exciton Zero-Dimensional Antimony-Based Metal Halides for White-light Emission and β-Ray Detection.

Self-trapped exciton (STE) emission, typified by antimony (Sb), with broadband characteristics, represents the next generation of materials for solid-state lighting and radiation detection. However, little is known about the multiexciton behavior of the Sb emission center. Here, we proposed a general approach for designing antimony-centered multi-exciton emitting materials through self-assembly. Benefitting from controllable multiexciton behavior, dual-band white light emission spanning the entire visible spectrum was achieved. Relying on the reduction of an effective atomic number brought by self-assembly, excellent scintillation response to β-rays was attained. This study offers unprecedented insight into hybrid single/triple STE emission and unveils new avenues for single-emitter white-light emission, as well as radiographic testing using low-risk β-rays as sources.

ADDON FOR BLENDER3D. AUTOMATION OF THE OBJECT TEXTURING PROCESS

Abstract. Today, the use of 3D visualization technologies is one of the key directions in the field of information technologies. The 3D direction has become extremely popular in many fields, such as architecture, interior design, game industry, medicine, automotive and other fields. This method opens up new opportunities for perception and interpretation of information, adding it to a three-dimensional virtual space. The topic of the research work is the creation of a software module (addon) for the Blender3D program, which will provide the user with a library of ready-made materials, divided by categories. This addon has similar functionality to Substance Painter and Quixel Mixer, the main functions of which are to create and adjust materials and textures for imported ready-made 3D models. The addon has its own name "QuickShader" and will provide the user with 8 shaders and 35 PBR materials. Throughout the development of the project, the Waterfall life cycle model was used, stability and a clear structure were put first, which helped to efficiently work through each step of creating an addon for the Blender program. In the conclusion to the scientific work, it can also be noted that the development of a software addon for Blender3D, which includes a library of shader operators and PBR materials, will greatly facilitate the work of users when assigning textures to objects on the scene. A library of shader operators makes it easy to implement and customize shaders for light, glass, and some metals, giving you more control over the visual aspect of the scene. PBR materials provide realism due to the accurate representation of physical properties using Physically Based Rendering technologies. This addon gives users the ability to interact more effectively with procedural materials, providing a quick means to create realistic renders. This module automates the creation of materials by providing a list of prepared shaders and textures that can be applied to scene objects. The user will be provided with a set of ready-made shaders (glass, light material, metals) and PBR materials (wood, fabric, metals, and others), which can be applied with one button on the module panel.

Thermal Conductivity of Polymers: A Simple Matter Where Complexity Matters.

Thermal conductivity coefficient κ measures the ability of a material to conduct a heat current. In particular, κ is an important property that often dictates the usefulness of a material over a wide range of environmental conditions. For example, while a low κ is desirable for the thermoelectric applications, a large κ is needed when a material is used under the high temperature conditions. These materials range from common crystals to commodity amorphous polymers. The latter is of particular importance because of their use in designing light weight high performance functional materials. In this context, however, one of the major limitations of the amorphous polymers is their low κ, reaching a maximum value of ≈0.4 W/Km that is 2-3 orders of magnitude smaller than the standard crystals. Moreover, when energy is predominantly transferred through the bonded connections, κ ⩾ 100 W/Km. Recently, extensive efforts have been devoted to attain a tunability in κ via macromolecular engineering. In this work, an overview of the recent results on the κ behavior in polymers and polymeric solids is presented. In particular, computational and theoretical results are discussed within the context of complimentary experiments. Future directions are also highlighted.

Sustainability and dialysis: the 4 main points for a green dialysis

Dialysis represents a big challenge for the environmental sustainability, because it is bound to high consumption of water and electricity, hazardous waste incineration and subsequent greenhouse gas emissions. In recent years, it has been recognized the urgent need to preserve our environment together with the people’s health, starting from making dialysis greener. This awareness has led to a new paradigm in the history of dialysis, the concept of Green Nephrology. The Italian Society of Nephrology published 10 affordable actions in the Position Statement with the aims to increase awareness, propose joint actions and coordinate industrial/social interactions. Starting from these, there are four key points to pave the way for environmental sustainability: 1) Sustainable technologies (i.e., machines, filters, water treatment systems, acid concentrates, lighter materials, electronic patient record); 2) Green dialysis centers; 3) Environmental improvement project, using tools to define targets and their monitoring; 4) Nurse role, as he is the main environmental sustainability promoter. To achieve Green Nephrology it’s necessary a partnership between all the stakeholders of the healthcare system. Since the growing awareness of the problem and the existence of ways to solve it, it’s time to act and the effective way to do it is to implement all the solutions provided in this article in an immediate future.

Evaluation of new Li2CaSiO4:Eu/ scintillation plastic phoswich for combined alpha-beta and gamma-neutron detectors

A phoswich-type detector element based on a new light inorganic scintillation material, Li2CaSiO4:Eu2+, and a plastic scintillator, EJ-200, was evaluated for separation of signals of neutrons, β-, α-particles and γ-rays. It has been shown that the use of scintillators in a phoswich with a quite large difference in the scintillation kinetics, by two orders of magnitude, despite the effect of excitation of inorganic material luminescence by scintillation of plastic, provides reliable discrimination of signals from the layers of the phoswich detector. The developed approach to constructing a detecting element can find applications for discrimination of α- and β-particles, as well as neutrons and γ-rays in combined α/β and γ-neutron detectors for radiometry and dosimetry. The separation of signals and measurement of the response when recording interaction products in the reverse β-decay reaction are of particular interest.

Up-conversion materials for solid-state lighting

AbstractConventional phosphor-converted white LEDs (WLEDs), using (Stokes) down-conversion light emission, suffer from a red deficiency that increases the Color Temperature towards “cool white light” above 5000 K. The present work describes a phosphor-Up-converted WLED approach that wishes to overcome this issue by achieving white light generation (WLG) through Up-conversion photoluminescence (UCPL), without energy losses due to Stokes shift and excited by a 980 nm LED instead of the more expensive blue LEDs. The UC materials include thin films of lanthanide (Ln)-doped aluminosilicate glass multilayers, alternating (Ln)-doped aluminosilicate and titania films in the form of 1-D photonic crystals and Ln ion-implanted materials. Sol-gel (SG) processing has been used as a low-cost high purity processing method to prepare titania, as well as aluminosilicate films containing Er3+, Tm3+ and Yb3+, for WLG and possible application as WLED materials. The total Ln content varied from a high of 22 mol% to as low as 5.8 mol%. The materials prepared have been characterized by UV-Vis-NIR (using a variable angle specular reflection accessory), plus FTIR and UCPL spectroscopies. The UC light emission was analyzed with the help of CIE chromaticity diagrams. Graphical abstract

Electron transporting bilayers for perovskite solar cells: Spray coating deposition of c-TiO2/m-SnO2-quantum dots

Herein we present a comparative study among different spray-coated nanometric mesoporous electron transporting layers (ETLs) in perovskite solar cells (PSC), namely m-TiO2, m-SnO2 and m-SnO2 quantum dots (m-SnO2QDs). The solutions used for deposition were prepared from commercial pastes and colloidal suspensions for m-TiO2 and m-SnO2. For m-SnO2QDs in-house QDs solutions were prepared. The formamidinium-methylamonium-potassium (FAMA@10 K) has been used as light absorber material in the fabricated PSCs. The structural, compositional and morphological studies, correlated with the photovoltaic performance of PSCs, indicate that the m-SnO2 QDs layer is the best candidate among the three investigated mesoporous ETLs. Compared with the suspensions used for the other two ETLs, the in-house prepared SnO2 QDs solution presents smaller agglomerates of nanoparticles and results in the formation of a thinner, more uniform and compact mesoporous ETL. The FAMA@10 K perovskite deposited on m-SnO2 QDs ETL presents a lower roughness, better uniformity and a higher amount of PbI2. Our work unveils that the SnO2 QDs solution can be easily produced in laboratory and when is deposited as mesoporous scaffold in a PSC with FAMA@10 K perovskite, the power conversion efficiency increases up to 14.90 %, being with up to 27 % larger than in the PSCs with m-TiO2 and m-SnO2 ETLs prepared from commercial solutions. By modeling the J-V dynamic hysteresis with more than 90 % match between the calculated and experimental J-V data, for all three types of mesoporous ETLs, the relevant parameters that explain the hysteresis magnitude and account for ionic-induced recombination processes in PSCs were determined.

Orbital torque switching in perpendicularly magnetized materials

The orbital Hall effect in light materials has attracted considerable attention for developing orbitronic devices. Here we investigate the orbital torque efficiency and demonstrate the switching of the perpendicularly magnetized materials through the orbital Hall material, i.e., Zr. The orbital torque efficiency of approximately 0.78 is achieved in the Zr orbital Hall material with the perpendicularly magnetized [Co/Pt]3 sample, which significantly surpasses that of the perpendicularly magnetized CoFeB/Gd/CoFeB sample (approximately 0.04). Such a notable difference is attributed to the different spin-orbit correlation strength between the [Co/Pt]3 sample and the CoFeB/Gd/CoFeB sample, confirmed through theoretical calculations. Furthermore, the full magnetization switching of the [Co/Pt]3 samples with a switching current density of approximately 2.6×106 A/cm2 has been realized through Zr, which even outperforms that of the W spin Hall material. Our finding provides a guideline to understand orbital torque efficiency and paves the way for developing energy-efficient orbitronic devices.

Front Cover

Journal of Biophotonics focuses on the interdisciplinary field of biophotonics, publishing cutting‐edge research on interactions between light and biological material. The journal covers photonics research in areas such as life sciences, medicine and biomedicine, environmental science, nutrition, biology, physics, and chemistry, ranging from fundamental research to the latest clinical applications.image

The structural, elastic, optoelectronic properties and hydrogen storage capability of lead-free hydrides XZrH3 (X: Mg/Ca/Sr/Ba) for hydrogen storage application: A DFT study

Perovskite hydrides are promising materials for hydrogen capacity application to achieve the US DOE on-board criteria. We have investigated novel perovskite hydrides XZrH3 (X: Mg/Ca/Sr/Ba) for H2 storage and transportation applications. In this study we investigates the physical properties of XZrH3 light materials for solid-state hydrogen storage application by incorporating the DFT framework with the CASTEP code. We have theoretically examined the structural, mechanical, electronic, optical, and hydrogen storage properties of these materials. The selected compounds were fully relaxed and optimized in the cubic phase space group Pm-3 m. Structural phase stability was confirmed through thermodynamic, and mechanical analyses. Mechanical properties, evaluated based on Poisson’s ratio, the Puagh’s ratio, and Cauchy pressure, indicate the ductile behavior with a preference for ionic bonding. The electronic structure analysis reveals the metallic behavior of these materials. Optical calculations were also performed to provide additional insights into the physical properties of H2 compounds. The gravimetric hydrogen storage capacities were calculated as 2.55, 2.25, 1.66, and 1.31 wt% for MgZrH3, CaZrH3, SrZrH3, And BaZrH3 hydrides respectively. The identified properties of XZrH3 suggest that these materials could significantly enhance hydrogen storage systems, with potential integration into existing energy technologies, offering a pathway toward more efficient and sustainable hydrogen-based solutions.

Pyrene‐Modified Blue Emitters for OLED Applications: Efficiency and Stability Advancements

AbstractBlue light materials have always posed a challenge in the OLED industry due to their high energy, which negatively impacts the stability of organic luminescent materials. Consequently, there is a significant disparity in efficiency and lifespan compared to red and green materials. In this study, we successfully synthesized three blue fluorescent luminescent materials with high fluorescence quantum efficiency by utilizing pyrene as the core. The 1,6‐positions of pyrene were substituted with diphenylamine and further modified with methoxy, isopropyl, and dibenzofuran. These modifications were introduced to enhance efficiency, increase spatial site resistance, and improve structural rigidity. Each structure exhibits a maximum current efficiency of over 8.2 cd/A and a maximum external quantum efficiency (EQE) of more than 5.8%. Notably, the compound N1,N6‐bis(4‐isopropylphenyl)‐N1,N6‐bis(2‐methoxyphenyl)pyrene‐1,6‐diamine (BD1), with methoxy modification, achieves a maximum current efficiency of 9.3 cd/A. Additionally, the compound N1,N6‐bis(dibenzo[b,d]furan‐4‐yl)‐N1,N6‐di‐o‐tolylpyrene‐1,6‐diamine (BD2) exhibits significantly less EQE roll‐off. This article provides valuable insights into the substitution‐based modification strategy for optimizing blue light performance in OLED applications.

Harvesting the tuning mechanism of strategic polychrome and white light emission in NapH dye based on excited state intermolecular proton transfer

Organic white light emitting (WLE) materials have sparked a research boom due to their promising applications in display devices, artificial lighting, and molecular sensors. However, the complex luminescence mechanism of full-spectra emitting materials has limited the development of white light materials with high stability and reproducibility. In this study, building on the full-spectra luminescent naphthimide dye (NapH) introduced by Xu et al., (Chin. Chem. Lett. 35(2024), 108348), we report the solvent-sensitive excited state proton transfer (ESPT) properties and white light emission mechanism in NapH. Our theoretical research results show that the ESPT process of NapH molecule is hindered in the low-polar solvent tetrahydrofuran (THF), so only the blue fluorescence from the Enol* is observed in the experiment. In contrast, in polar solvents such as water (H2O) and methanol (MeOH), the formation of strong intermolecular hydrogen bonds successfully initiates the ESPT process, leading to the dual fluorescence observed in experiments, with blue emission from the Enol* and red emission from the Nap anion. In essence, different solvent environments can adjust several emission colors. Furthermore, we theoretically verify that the optimal white light emission can be achieved when the mixed solvent ratio of dimethyl sulfoxide (DMSO) and dioxane (DIOX) is 5:5, which aligns well with experimental results. More importantly, we elucidate the specific WLE mechanism from multiple perspectives, including potential energy curves and electron spectra. Our work not only displays the interaction models of NapH molecule in various solvents, but also reveals the underlying luminescence mechanism, thus providing a valuable theoretical reference for the development and advancement of new white light materials.