Light Absorption Efficiency Research Articles

Photodynamic therapy with photodegradable photosensitizers.

Photodegradable photosensitizers have gained significant attention in recent years due to their potential advantages in photodynamic therapy. By degrading upon light exposure, these photosensitizers reduce post-treatment drug residues, minimize toxicity, and enhance the safety and precision of therapy. This review provides an overview of the design and current applications of photodegradable photosensitizers, addressing challenges related to light absorption efficiency, toxicity of degradation products, and tissue penetration. Furthermore, future optimization strategies, including chemical modifications, nanocarrier integration, and combination therapies, are discussed.

Multiscale Biomimetic Evaporators Based on Liquid Metal/Polyacrylonitrile Composite Fibers for Highly Efficient Solar Steam Generation

Solar steam generation (SSG) offers a cost-effective solution for producing clean water by utilizing solar energy. However, integrating effective thermal management and water transportation to develop high-efficiency solar evaporators remains a significant challenge. Here, inspired by the hierarchical structure of the stem of bird of paradise, a three-dimensional multiscale liquid metal/polyacrylonitrile (LM/PAN) evaporator is fabricated by assembling LM/PAN fibers. The strong localized surface plasmon resonance of LM particles and porous structure of LM/PAN fibers with interconnected channels lead to efficient light absorption up to 90.9%. Consequently, the multiscale biomimetic LM/PAN evaporator achieves an outstanding water evaporation rate of 2.66kgm-2h-1 with a solar energy efficiency of 96.5% under one sun irradiation and an exceptional water rate of 2.58kgm-2h-1 in brine. Additionally, the LM/PAN evaporator demonstrates a superior purification performance for seawater, with the concentration of Na+, Mg2+, K+ and Ca2+ in real seawater dramatically decreased by three orders to less than 7mgL-1 after desalination under light irradiation. The multiscale LM/PAN evaporator with hierarchical structure regulates the water transportation as well as thermal management for highly effective solar-driven evaporation, providing valuable insight into the structural design principles for advanced SSG systems.

Accompanying Bi Clusters as Charge Mediators Effectively Enhance Synergetic Redox of Bi2Sn2O7/ZnIn2S4 S-Scheme Heterostructure Composites.

Achieving synergistic oxidation and reduction represents a significant challenge in the field of photocatalysis. In this study, the hydrothermal/in situ construction of Bi atom clusters within Bi2Sn2O7/ZnIn2S4 (BSO/ZIS) heterostructures is reported. These clusters exhibit self-accelerating charge-transfer mechanisms facilitated by internal electric fields and bonding bridges, resulting in highly efficient light absorption and charge-transfer capabilities. In situ X-ray photoelectron spectroscopy (XPS) and Kelvin probe force microscopy (KPFM), as well as theoretical calculations, indicate that the canonical induction and promotion of electrons and holes by the Bi clusters lowers the activation energy of CHO* generation, allowing simultaneous CO2 reduction and toluene oxidation over the catalyst, and enhances proton-coupling and electron-transfer processes, resulting in a unique reaction mechanism. The CO2 and toluene as reactant, the Bi-Bi2Sn2O7/ZnIn2S4 (B-BSO/ZIS) heterostructure achieves a CO2 reduction rate to CO of 726.3µmol g-1h-1 (99.9% selectivity) and a toluene oxidation rate to benzaldehyde of 2362.0µmol g-1h-1 (98.0% selectivity), which increases in activity of 14.6 and 5.7 times compared to pristine ZnIn2S4. This study underscores the significance of modulating the photocatalytic pathway through the strategic selection of metal clusters and reactants, contributing to the rational design of photocatalysts for enhanced CO2 adsorption and stabilization of *H.

CsSnI3 Quantum Dots as a Multifunctional Interlayer for High‐Efficiency Bilayer Perovskite Solar Cells

AbstractPerovskite solar cells (PSCs) have garnered significant interest due to their potential for high performance at low cost. While single‐junction PSCs have surpassed 26% efficiency, they are nearing their theoretical limits. Introducing dual absorber layers can broaden the spectral absorption range, enhancing performance. This study explores a zero‐dimensional/three‐dimensional (0D/3D) bilayer structure combining three‐dimensional (3D) FAPbI3 with zero‐dimensional (0D) cesium tin triiodide (CsSnI3) quantum dots (QDs) as an interfacial modification layer. The CsSnI3 QDs establish a cascade energy level structure, improving charge transfer efficiency at the perovskite‐hole transport layer (HTL) interface. Their narrow bandgap enhances light absorption efficiency, boosting hole extraction and short‐circuit current density. Incorporating CsSnI3 QDs into PSCs significantly improves the power conversion efficiency from 22.99% to 25.72% compared to 3D perovskite solar cells without the CsSnI3 QD interlayer. Also, surface‐passivated CsSnI3 QDs with hydrophobic ligands provide moisture resistance and interfacial passivation, increasing stability. Using perfluorooctanoic acid (PFA) to modify CsSnI3 QDs further enhances moisture resistance, allowing PSCs to maintain 85% of initial efficiency for over 60 days at 25% relative humidity without encapsulation, demonstrating significant stability improvements. The incorporation of CsSnI3 QDs in PSCs notably increases power conversion efficiency.

Photothermal superhydrophobic coupled functional surface with active anti/de-icing performance

Photothermal superhydrophobic coupled functional surface with active anti/de-icing performance

Enhancing Efficiency of Lead‐Free Cs2TiIxBr6‐x Perovskite Solar Cells Through Linear and Parabolic Grading Strategies: Toward 31.18% Efficiency

ABSTRACTThe most amazing environmentally friendly energy source is solar energy, which can be captured with the aid of photovoltaic (PV) cells. Perovskite solar cells (PSCs) that are hybrid (organic–inorganic) have demonstrated remarkable PV ability. The advantages of halide‐based perovskite are numerous and include cheap cost, high efficiency, and simplicity in fabrication. Due to their poisonous nature, lead (Pb)‐based PSCs often pose a concern to the environment. They also have other drawbacks, such as stability problems, problems with scalability, and health risks associated with Pb exposure. Thus, the primary intent of this study is to examine the Pb‐free, inorganic titanium‐based perovskite complex Cs2TiIxBr6‐x, which serves as the active layer. When compared with other elements, titanium is nontoxic, strong, affordable, and easily accessible. To improve the efficiency of lead‐free (Au/CuSbS2/Cs2TiIxBr6‐x/CdS/FTO) device structure, both linear and parabolic grading methods are used in the simulation. The perovskite composition Cs2TiIxBr6‐x is a mixed halide system, with different amounts of iodine (I) and bromine (Br) ions integrated into the crystal lattice. Within the halide system, “x” indicates the percentage of iodide ions that replace bromide ions. Light absorption and energy conversion efficiency in solar cells may be maximized by fine tuning the material's band gap by varying “x,” which can range from 0 to 6. When the active layer is graded linearly, the band gap is adjusted by adjusting the composition x, which ranges from 0 to 6, throughout the active layer's thickness. The bending factor changes from 0 to 1 in the case of parabolic grading of the Cs2TiIxBr6‐x layer, indicating an enhancement in the device's PCE as a result of high wavelength photon absorption. Our simulations show a significant improvement in PCE, with an astounding result of 31.18% for parabolic grading, a 7.93% increase above PCE from linear grading, which is 28.89%. Other noteworthy metrics that exhibit exceptional outcomes include JSC 34.36 mA.cm−2, FF 86.81%, and VOC 1.0452 V. The stability in the output of the device in the realistic temperature range confirms the highly stable nature of the proposed PSC device. These results show how effectively our approach improves the efficiency and effectiveness of Pb‐free PSC's. As we are interested in this realistic environmental temperature range of the whole world, we proposed that Cs2TiIxBr6‐x‐based PSCs are highly suitable and stable for the real‐time experiment, which is the need of PSCs nowadays.

Electronic, optical and photocatalytic water splitting properties of two-dimensional monolayers of Janus Cd2XY (X = S, Se; Y = Se, Te; X ≠ Y): A first-principles study

Abstract Two-dimensional Janus materials play a significant role in the advancement of optoelectronic devices and photocatalytic water splitting. In the present work, the stability, electronic structure, transfer properties, optical properties, and photocatalytic water-splitting properties of three Janus monolayers (Cd2SSe, Cd2STe, and Cd2SeTe) were investigated by using first-principles calculations. It is found that they are well-stabilized with a band gap Eg of 1.14, 1.49, and 2.32 eV (the photocatalytic water splitting threshold being 1.23 eV) respectively, all of which correspond to direct band gap semiconductors. They all demonstrate excellent electron mobility and hole mobility, along with high light absorption in the visible range. The band-edge potential of Cd2SSe crosses the potential for the redox reaction of water; Applying biaxial tensile strain enhances its light absorption efficiency and reduces the band gap, thereby increasing the performance of photocatalytic water splitting. Each step of the HER and OER reaction process with Cd2SSe as a catalyst can be carried out spontaneously under light conditions. The results indicate that the three Janus monolayers hold significant promise in next-generation optoelectronic devices and photocatalysts.

Distinct Promotion of PEC Water Oxidation of Ta2O5/α-Fe2O3/Co-Ni PBA via Coupling Ni 3d with O 2p.

The development of robust and effective photoanodes is crucial for photoelectrochemical hydrogen production via total water splitting. Herein, the Ta2O5/α-Fe2O3/Co-Ni PBA (TFPB-1) photoanode was constructed by the compositing n-type Ta2O5 and n-type α-Fe2O3 followed by the deposition of p-type Co-Ni PBA. The IPCE of TFPB-1 was increased to 35.4% compared to 13.9% for Ta2O5 owing to the significantly improved light absorption efficiency, carrier separation efficiency and injection efficiency. The TFPB-1 achieved a current density of 2.78 mA cm-2 at 1.23 V (vs RHE), which was around 18.5 times that of Ta2O5. The OER overpotential over TFPB-1 was reduced to 0.59 V compared to 1.13 V for Ta2O5, resulting in a substantial reduction in the free energy of PEC water oxidation over TFPB-1. As a result, TFPB-1 exhibited remarkably enhanced photoelectrocatalytic activity for oxygen evolution through water oxidation.

Polarization-Dependent Plasmon-Induced Doping and Strain Effects in MoS2 Monolayers on Gold Nanostructures.

Monolayers of transition-metal dichalcogenides, such as MoS2, have attracted significant attention for their exceptional electronic and optical properties, positioning them as ideal candidates for advanced optoelectronic applications. Despite their strong excitonic effects, the atomic-scale thickness of these materials limits their light absorption efficiency, necessitating innovative strategies to enhance light-matter interactions. Plasmonic nanostructures offer a promising solution to overcome those challenges by amplifying the electromagnetic field and also introducing other mechanisms, such as hot electron injection. In this study, we investigate the vibrational and optical properties of MoS2 monolayer deposited on gold substrates and gratings, emphasizing the role of strain and plasmonic effects using conventional spectroscopic techniques. Our results reveal significant biaxial strain in the supported regions and a uniaxial strain gradient in the suspended ones, showing a strain-induced exciton and carrier funneling effect toward the center of the nanogaps. Moreover, we observed an additional polarization-dependent doping mechanism in the suspended regions. This effect was attributed to localized surface plasmons generated within the slits, as confirmed by numerical simulations, which may decay nonradiatively into hot electrons and be injected into the monolayer. Photoluminescence measurements further demonstrated a polarization-dependent trion-to-A exciton intensity ratio, supporting the hypothesis of additional plasmon-induced doping. These findings provide a comprehensive understanding of the strain-mediated funneling effects and plasmonic interactions in hybrid MoS2/Au nanostructures, offering valuable insights for developing high-efficiency photonic devices and quantum technologies, including polarization-sensitive detectors and excitonic circuits.

Identification and Analysis of Melon (Cucumis melo L.) SHMT Gene Family Members and Their Functional Studies on Tolerance to Low-Temperature Stress

Melon (Cucumis melo L.) is a significant cash crop globally and is cherished for its sweet and flavorful fruits, as well as its high nutritional values. However, its yield and quality are limited by various factors, including drought, salinity, and low temperatures. Low temperatures are one of the primary factors influencing the growth and development of melons, diminishing the viability, germination, and growth rate of melon seeds. Concurrently, low temperatures also reduce light absorption efficiency and fruit yields, thereby affecting melon growth and development. Serine hydroxymethyltransferase (SHMT), a conserved phosphopyridoxal-dependent enzyme, plays a crucial role in plant resistance to abiotic stressors. In this study, eight CmSHMT family genes were identified from the melon genome. We predicted their chromosomal locations, physicochemical properties, gene structures, evolutionary relationships, conserved motifs, cis-acting elements of promoters, and tissue-specific expression patterns. The expression levels of CmSHMT family genes in response to low-temperature stress was then analyzd using qRT-PCR. The phylogenetic results indicated that these CmSHMT genes were classified into four subfamilies and were unevenly distributed across five chromosomes, with relatively high conservation among them. Furthermore, our investigation revealed that the promoter regions of the CmSHMT family genes contain many cis-acting elements related to phytohormones, growth, and various stress responses. The relative expression levels of CmSHMT3, CmSHMT4, CmSHMT6, and CmSHMT7 were higher under low-temperature stress compared to the control group. Notably, the promoter region of CmSHMT3 contains cis-acting elements associated with low-temperature response (LTR) and abscisic acid response (ABRE). It is suggested that the mechanism through which CmSHMT3 responds to low-temperature stress treatments may be associated with hormonal regulation. These findings provide a foundation for the further exploration of CmSHMT family genes in melon and their functional roles in response to low-temperature stress, and they provide a theoretical basis for the targeted breeding of superior melon varieties with enhanced tolerance to low temperatures.

Enhanced dual-mode terahertz absorption in a graphene-dielectric metasurface by quasi-bound states in the continuum

A graphene-dielectric metasurface driven by quasi-bound states in the continuum (BICs) is proposed for enhanced dual-mode absorption in the terahertz (THz) regime. The graphene-dielectric metasurface is composed of a periodic array of cross-shaped slabs and monolayer graphene. By introducing symmetry perturbation for the cross-shaped slab metasurface, the symmetry-protected BICs transform into quasi-BICs. Subsequently, monolayer graphene is introduced to the cross-shaped slab metasurface to demonstrate the potential of the enhanced dual-mode THz absorption. When the system reaches the critical coupling, each quasi-BIC can achieve the theoretical maximum absorption, with the Q-factor reaching 9033 and 2432, highlighting the unique capacity for tuning and efficient light absorption. This work provides a valuable approach for applications in absorption and manipulation of THz waves.

Optimizing carrier transport properties in the intrinsic layer of a-Si single and double junction solar cells through numerical design

This research aims to improve the performance of a-Si: H solar cells, particularly in terms of carrier transport properties, through a numerical design approach utilizing AFORS-HET simulation software. By performing a series of rigorous computer simulations, we explore the potential regulation of the intrinsic layer thickness, carrier mobility, loading factor, and density of states (DoS) distribution in the solar cell's intrinsic layer. Recombination losses are reduced, and light absorption efficiency is significantly increased when the intrinsic layer thickness is adjusted, as shown by simulation findings. Moreover, reduction of transit times and enhancement of the total efficiency of the solar cells depend on increased carrier mobility. Parameters can be adjusted to attain optimal performance under various operating situations by adjusting the DoS and load factors. Furthermore, the simulations provide insightful information about the interactions between the junctions in solar cells with double junctions. Our results of this research provide an important contribution to efforts to develop more efficient and sustainable a-Si: H solar cells and emphasize the importance of numerical design approaches in photovoltaic technology.

A high-efficiency blue-LED-excitable broadband Cr3+/Ni2+ co-doped garnet phosphor toward next-generation spectroscopy applications

Cr3+/Ni2+ introduces a strong crystal field Ca3Al2Ge3O12 host to obtain a coordinated energy level position. Heavily doped Cr3+ selectively transfers energy to Ni2+, significantly enhancing the absorption efficiency of blue light.

Photocatalytic degradation of tetracycline antibiotics and elimination of N-nitrosodimethylamine formation potential by BiOCl/ZnIn2S4 heterostructure under visible-light irradiation.

Photocatalysis is an effective method for removing tetracycline antibiotics, which are important precursors to the potential carcinogen N-nitrosodimethylamine (NDMA). Herein, a BiOCl/ZnIn2S4 heterojunction was successfully synthesized using a simple hydrothermal method. This heterojunction was applied for the first time to degrade various tetracycline antibiotics and reduce NDMA formation potential (NDMA-FP) under visible-light irradiation. Characterization of surface morphology, crystal structure, chemical composition and photoelectrochemical properties revealed that the BiOCl/ZnIn2S4 heterojunction significantly improved light absorption, charge transport and carrier separation efficiency, thereby enhancing photocatalytic performance. The BiOCl/ZnIn2S4 catalyst achieved high degradation efficiencies of 88.0%, 90.7%, 88.7% and 91.7% for tetracycline, minocycline, chlortetracycline and doxycycline, respectively, within 60min of visible-light irradiation. Additionally, it exhibited the lowest NDMA-FP values of 1.5%, 3%, 0.9% and 1.4%, respectively. Radical trapping studies and EPR experiments identified •O2- and •OH radicals as the primary reactive species involved in the photocatalytic process. Analysis of the degradation intermediates and structure-activity relationships indicated that the variations in NDMA-FP were closely associated with the number of dimethylamine groups in the antibiotics and the stability of the resulting carbocations. Notably, the BiOCl/ZnIn2S4 catalyst presented satisfactory stability and positive tetracycline degradation in real antibiotic wastewater. Incorporating BiOCl/ZnIn2S4-loaded nonwoven fabric into a continuous-flow reactor efficiently degraded tetracycline in real wastewater under visible light. This work provides new insights on developing Z-scheme photocatalysts for the simultaneous degradation of various antibiotics and highlights their potential as commercially viable photocatalytic system.

Sustainable solar-powered seawater desalination enabled by phosphorene-decorated watermelon-like phase-change microcapsules

Sustainable solar-powered seawater desalination enabled by phosphorene-decorated watermelon-like phase-change microcapsules

Manipulation of trions to enhance the excitonic emission in monolayer p-MoS2 and its hetero-bilayer by reverse charge injection.

Monolayer 2D transition metal dichalcogenides (TMDs) are known for their direct bandgaps and pronounced excitonic effects, which facilitate efficient light absorption and high photoluminescence (PL). In this study, we report a significant enhancement in PL emission from monolayers of p-type molybdenum disulfide (p-MoS2), fabricated on conductive substrates-such as indium tin oxide (ITO) and gold (Au). We attribute this behaviour to the reverse injection of charge carriers from substrates to p-MoS2 and the subsequent localization of electrons and holes in the substrate and p-MoS2, respectively. Such injection of charge carriers was suppressed when few-layer graphene (FLG) was used as a barrier layer. Further investigation of the PL emission characteristics from a vertically stacked hetero-bilayer (the p-n interface) of p-MoS2 and n-MoSe2 revealed a single resonant high-emission PL peak at 1.64 eV with the PL emission from this heterostructure significantly higher than that from free-standing monolayers. This finding contrasts sharply with the PL quenching often seen in hetero-bilayers with an n-n interface. These findings offer valuable insights into the fundamental optical and electronic properties of 2D TMDs and their heterostructures, which are essential for optimizing these materials for optoelectronic applications.

Photoelectric characteristic of hybrid thin-film solar cells and metasurface absorbers

Abstract As the demand for high-efficiency, low-cost solar cells continue to increase, existing thin-film solar cells still face many challenges in terms of light absorption efficiency and charge transport performance. To address these issues, we design and study a PEDOT:PSS/CdTe hybrid thin-film solar cell structure combined with a metasurface absorber layer. We use a metasurface structure with a tetragonal embedded ring resonator pattern in the CdTe absorber layer. This structure can produce a strong electric and magnetic field localization effect on the surface of the absorption layer, improving the light absorption rate of the battery. At the same time, the introduction of organic polymer materials (PEDOT: PSS) optimizes the electrode interface quality and reduces the interface defects and composite losses between materials, and further improves the photoelectric conversion efficiency (PCE) of the battery. we introduce traditional absorption enhancement methods (titanium nanoparticle arrays and pyramid TiO2 arrays) to this structure. The solar cell proposed has a spectral response rate of 96.71% and its PCE reaches 35.66%. The research indicates that the new structure holds significant potential for the application of high-efficiency solar cells, offering new ideas for the design and manufacture of solar cells in the future.

Thickness-Dependent Electrical Simulation of Ternary Layer-by-Layer Organic Solar Cell

Recently, researchers have been interested in incorporating a third component into the active layer of organic solar cells (OSC). Introducing a third component aims to improve the efficiency of light absorption, charge separation, and transport within the solar cell. It is widely observed that varying active layer thicknesses result in different device competencies due to the behaviour of charge transportation and charge collection in such volume morphology of active layer. This paper incorporated layer-by-layer (LbL) devices based on BTR-Cl as donor and IT-2Cl as acceptor with Y6 acceptor as a third component in the active layer. These devices had been electrically characterized using organic and hybrid material nano (OghmaNano) simulation tool. A thickness ranging between 40 nm and 100 nm of each material in the active layer was evaluated in this simulation. This simulation shows the current-voltage (I-V) characteristics for ternary LbL OSC devices at various thicknesses. The short circuit current density (Jsc), open circuit voltage (Voc), and fill factor (FF) for each device's active layer thickness were also provided. At a thickness ratio of 50:60:50 nm (BTR-Cl to Y6 to IT-2Cl) and 100 mW cm-2, AM1.5 incident solar radiance, the maximum attainable efficiency, 12.1%, was found.

Model Calculation of Enhanced Light Absorption Efficiency in Two-Dimensional Photonic Crystal Phosphor Films

Model Calculation of Enhanced Light Absorption Efficiency in Two-Dimensional Photonic Crystal Phosphor Films

Green synthesis of novel chitosan-graphene oxide-silver nanoparticle nanocomposite for broad-spectrum antibacterial applications

Abstract In this study, a novel nanocomposite composed of chitosan, graphene oxide, and silver nanoparticles (CS-GO-Ag NPs) is presented and synthesized using pulsed laser ablation. Characterization techniques, including X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Spectroscopy EDX, and UV-visible spectroscopy, confirm successful synthesis. The XRD results reveal that the CS-GO-Ag NPs exhibit crystalline structures with an average crystallite size of approximately 30 nm. FE-SEM analysis shows a heterogeneous mixture of nanoparticles, ranging in size from 32.38 to 174.9 nm. The EDX spectra elucidate the elemental composition, while UV-Vis spectroscopy indicates strong interactions among the components, yielding a direct bandgap of 2.33 eV and an indirect bandgap of 1.2 eV, suggesting efficient light absorption and emission for applications in Light emitted Diode (LEDs) and solar cells. Furthermore, the CS-GO-Ag NPs nanocomposite displays enhanced antibacterial activity against both gram-negative and gram-positive bacteria when it compared to its individual components. According to characterization tests, well-dispersed silver nanoparticles were formed into a ternary nanocomposite, successfully. The enhanced antibacterial capabilities including increased bacterial cell membrane disruption and oxidative stress can be attributed to the synergistic interaction between the components. The outcomes highlight the CS- GO-Ag NPs nanocomposite's potential as a promising antimicrobial agent for numerous applications including the biomedical fields and water treatment industries.