Light Storage Research Articles

Progress of Photocapacitors.

In response to the current trend of miniaturization of electronic devices and sensors, the complementary coupling of high-efficiency energy conversion and low-loss energy storage technologies has given rise to the development of photocapacitors (PCs), which combine energy conversion and storage in a single device. Photovoltaic systems integrated with supercapacitors offer unique light conversion and storage capabilities, resulting in improved overall efficiency over the past decade. Consequently, researchers have explored a wide range of device combinations, materials, and characterization techniques. This review provides a comprehensive overview of photocapacitors, including their configurations, operating mechanisms, manufacturing techniques, and materials, with a focus on emerging applications in small wireless devices, Internet of Things (IoT), and Internet of Everything (IoE). Furthermore, we highlight the importance of cutting-edge materials such as metal-organic frameworks (MOFs) and organic materials for supercapacitors, as well as novel materials in photovoltaics, in advancing PCs for a carbon-free, sustainable society. We also evaluate the potential development, prospects, and application scenarios of this emerging area of research.

Tailoring the physical parameters of ferroelectric liquid crystal mixture with cadmium selenide quantum dots

ABSTRACT Present studies demonstrate the dispersion effect of cadmium selenide quantum dots on ferroelectric liquid crystal mixture properties. Varying concentrations of cadmium selenide quantum dots (0.05 wt.%, 0.10 wt.% and 0.50 wt.%) have been taken to investigate its influence on the physical parameters of ferroelectric liquid crystal mixture KCFLC 10R. Phase transition, textural, electro-optical and photoluminescence studies have been performed in planar aligned cells. The presence of QDs disturbs the geometrical symmetry and molecular tilt of ferroelectric liquid crystal molecules which results in the modification of physical parameters of ferroelectric liquid crystal. It has been observed that doped samples have shown decrement in spontaneous polarisation and rotational viscosity. However, there is an improvement in the response time of the doped samples. The reduction in the spontaneous polarisation with voltage signifies that doped samples can operate at low voltage (~6 V) as compared to ferroelectric liquid crystal mixture (~12 V). Photoluminescence studies reveal that all the samples absorb UV light ~340 nm and produce visible emission at ~ 400 nm which can behave as UV light storage and high contrast display. This would be beneficial for luminescent displays as well as UV to visible light conversion applications.

Changes in the structural and physicochemical characterization of pea starch modified by Bacillus-produced α-amylase

In this study, changes in structural and physicochemical properties of pea starch treated with Bacillus-produced α-amylase were determined. The results showed that enzymatically modified pea starch had lower amylose content and granule size but higher branching degree and relative crystallinity. After enzyme hydrolysis, the distribution of A and B1 chains slightly decreased, while the distribution of B2 and B3 chains increased lightly. Enzymatic hydrolysis preferentially occurred in the amorphous region and cannot change the crystalline structure of pea starch. Moreover, pea starch showed lower light transmittance, peak viscosity, breakdown viscosity, pasting temperature, shear viscosity, storage modulus and loss modulus, while the oil adsorption capacity and gelatinization enthalpy significantly increased with increasing α-amylase hydrolysis time. Correlation analysis indicated that α-amylase hydrolysis had different effects on different pea varieties. This research could provide ideas for exploring new applications for enzymatically modified pea starch in food industry. Industrial relevanceThis study found that Bacillus-produced α-amylase significantly changed the amylose content, granule size and viscosity of pea starch, which was helpful to further investigate the modified starch. This technology is expected to widen the applications of pea starch modified by Bacillus-produced α-amylase in food industry, for example as thickener, stabilizer and beverage, to improve the texture, stability and shelf-life of various food products.

Dynamic light storage based on controllable electromagnetically induced transparency effect

We analytically and numerically investigate a signal light storing mechanism based on the controllable electromagnetically induced transparency (EIT) effect. We demonstrate that the isolation between the waveguide and the cavities cannot be achieved instantly as soon as the two cavities are tuned into resonance, no matter the index tuning rate is ultrafast or slow. We also investigate the temporal evolution features of the intracavity energy when the pulse during time is prolonged. We find many periodical oscillations of the trapped energy in both cavities, and they are entirely complementary. Our analysis shows that the adiabatic wavelength conversion in both cavities and a phase difference π between them play critical roles in this phenomenon.

Perovskite-Based Nanostructures for Fluorescence Afterglow Anticounterfeiting

Advanced fluorescence anti-counterfeiting technology has attracted the attention of researchers and encourages people to develop more materials with more colors and functions. Here, in order to achieve a full-band afterglow in the visible light region, we designed a composite CsPbI3-CsPbBr3/Sr2MgSi2O7:Eu2+,Dy3+@SiO2, which is composed of nanoscale all-inorganic cesium lead perovskite quantum dots (PQDs) and long-afterglow luminescent materials Sr2MgSi2O7:Eu2+,Dy3+ (SMS). SMS is used to store light energy, and PQDs are used to control afterglow emission colors; through their energy transfer, the afterglow colors can be adjusted in the visible region. SiO2 is used as the coating material to improve the temporary stability of the nanocomposite. The composite mixed with oleic acid (OA) can be used as a dye, which exhibits different emitting colors and afterglow colors under different excitation environments. This research provided an idea for using long-afterglow luminescent materials and PQDs in the field of fluorescence anti-counterfeiting by double anti-counterfeiting of fluorescence and afterglow.

Energy Optimal Scheduling Method of Microgrid with Wind and Solar Storage Based on Demand Response

In the operation of a microgrid with wind and light storage, energy dispatching will directly affect its operating cost, which is a core technology of microgrid operation. This paper designs an energy optimization method for a microgrid with wind and solar storage based on demand response to realizing more scientific micro-power energy scheduling. Considering the wind-solar storage microgrid’s lowest demand response cost and other comprehensive costs, an energy-optimal scheduling model of the wind-solar storage microgrid is constructed. The model sets the constraints of energy storage devices and ties line transmission power and power balance. A model-solving algorithm based on an improved particle swarm optimization algorithm is designed to realize the optimal energy scheduling of wind and solar storage microgrids. The experimental results show that the cost of microgrid operation has decreased in winter and summer after the optimal scheduling is implemented using the design method, and an excellent economic operation effect has been achieved.

Research on power balance control method of microgrid energy storage unit

In the isolated island operation of microgrids, affected by the different equivalent circuit impedance between distributed generators, the traditional droop control cannot evenly divide the reactive power borne by distributed generators according to the different line impedance. Therefore, firstly, the reasons affecting power sharing are analyzed, and then an improved droop control method based on traditional droop control is proposed; that is, the time change rate of voltage is used as the droop variable, and a voltage recovery mechanism is added to the reactive droop controller, in order to adjust the reciprocal of voltage to zero in the steady state, so as to stabilize the voltage. Aiming at the problem that the droop controller cannot always realize the equal distribution of reactive power, a voltage compensation link suitable for improved droop control is designed and added to eliminate the line impedance difference between distributed generators and improve the accuracy of reactive power distribution. Finally, the effectiveness and feasibility of the proposed control strategy are verified by building a “wind light storage load” microgrid simulation model on the MATLAB / Simulink platform.

Electromagnetically induced transparency-like effect in a lithium niobate resonator via electronic control

In this study, we theoretically proposed a method to achieve an electromagnetically induced transparency (EIT)-like effect in a whispering gallery mode resonator (WGMR) and experimentally validated the method in a lithium niobate (LN) device. Benefitting from the electro-optic and inverse piezoelectric effects of the LN material, two modes of the LN WGMR that are close in frequency can be tuned at different tuning rates, resulting in EIT-like resonance lineshapes. By varying the electric field applied to the LN WGMR, the full dynamic of the EIT-like phenomenon can be precisely controlled. The experimental results agreed well with the calculations based on the coupled mode theory. Moreover, we observed a hysteresis resulting from the photorefractive effect of LN. We believe our proposed method and demonstrated devices offer a way to control an EIT-like effect, which could have potential applications in light storage, quantum information processing, and enhanced sensing techniques.

A stable microporous framework with multiple accessible adsorption sites for high capacity adsorption and efficient separation of light hydrocarbons

Metal-organic frameworks (MOFs), a type of designable porous materials, are effectively employed to realize light hydrocarbons storage and separation in favor of energy conservation and environmental protection, superior to traditional separation technology. Significantly, a novel MOF, Ni2(L)2(HCOO)2·4H2O (1) has been constructed from a bifunctional group ligand of 3-hydroxy-4-(4H-1,2,4-triazol-4-yl) benzoic acid ligand (HL). MOF 1 possesses stable porous structure with narrow channels functionalized with multiple accessible adsorption sites of hydroxy group, carboxyl oxygen atoms from the L− and HCOO−, exhibiting a well trade-off between good capacity and selectivity for light hydrocarbons. The single-component sorption isotherm results of Ni2+ based MOF not only shows good gas sorption capacity for light hydrocarbons of C2H2, C2H6, C2H4, C3H8, and greenhouse gas CO2, especially remarkable uptake for C2H2 (122.0 cm3 g−1 at ambient condition), but also favorable selectivity for binary mixtures of C2H2/CH4, C2H6/CH4, C3H8/CH4, C2H4/CH4, C2H2/C2H4 as well as C3H8/C2H6/CH4 ternary mixture, as confirmed by ideal adsorbed solution theory (IAST) calculations, and dynamic breakthrough experiment. Grand canonical Monte Carlo (GCMC) simulation reveals the multiple synergism of accessible adsorption sites including functional OH groups, carboxylate groups, HCOO− and π···π stacking interaction between guest molecules and host-pore are crucial to contribute selective gas adsorption of light hydrocarbons.

Designing ABC-6 family small pore zeolites by epitaxial growth approach

Aluminosilicate small pore zeolites belonging to ABC-6 family play crucially important roles in the high methanol conversion with the high selectivity of light olefins, gas separation and storage, and selective catalytic reduction of NOx. In this work, we report a general method, called the epitaxial growth approach, for designing ABC-6 family small pore zeolites. It is mainly realized through the epitaxial growth on the nonporous SOD-type zeolite in the presence of inorganic cations (Na+ and K+) combined with a variety of organic structure directing agents (OSDAs). In this case, a series of ABC-6 family small pore zeolites such as ERI-, SWY-, LEV-, AFX-, and PTT-type zeolites have been successfully synthesized within a few hours. More importantly, the advanced focused ion beam (FIB) and the low-dose high-resolution transmission electron microscopy (HRTEM) imaging technique have been utilized for unraveling the zeolite heterojunction at the atomic level during the epitaxial growth process. It turns out (222) crystallographic planes of the SOD-type zeolite substrate provide unique pre-building units, which facilitate the growth of targeted ABC-6 family small pore zeolites along its c-axis. Moreover, the morphologies of ERI-type zeolite can also be tuned through the epitaxial growth approach, achieving a longer lifetime in the methanol conversion.

Effects of sucrose degradation product furfural on cyanidin-3-O-glucoside: Mechanism of action, stability, and identification of products in sugar solutions

Anthocyanins are often affected by the sweetener sucrose during processing, which is closely related to its typical degradation product, furfural (Ff). However, the specific mechanism is unclear. In this study, Ff and cyanidin-3-O-glucoside (C3G) were used to explain the mechanism of the effect. The results showed that Ff destabilized anthocyanins by chemically reacting with C3G to generate three new adducts. Meanwhile, the color of the C3G solution changed from bright red to dark purple, and the value of the color difference (ΔE) increased significantly by 2.69. Furthermore, the new adducts were less stable than C3G and continued to promote the degradation of C3G when they coexisted with it. The above adducts were also detected in sugar solutions supplemented with C3G, and these adducts were more likely to accumulate under light storage conditions. These results provide a theoretical basis for reducing anthocyanin loss in food processing.

A photonic integrated chip platform for interlayer exciton valley routing

Interlayer excitons in two-dimensional semiconductor heterostructures show suppressed electron–hole overlap resulting in longer radiative lifetimes as compared to intralayer excitons. Such tightly bound interlayer excitons are relevant for important optoelectronic applications, including light storage and quantum communication. Their optical accessibility is, however, limited due to their out-of-plane transition dipole moment. In this work, we design a complementary metal–oxide–semiconductor-compatible photonic integrated chip platform for enhanced near-field coupling of these interlayer excitons with the whispering gallery modes of a microresonator, exploiting the high confinement of light in a small modal volume and high-quality factor of the system. Our platform allows for highly selective emission routing via engineering an asymmetric light transmission that facilitates efficient readout and channeling of the excitonic valley state from such systems.

Constructing C-rich polymeric carbon nitride homojunctions for enhanced storage capacity of photo-rechargeable batteries

The light-induced accumulation of long-lived trapped electrons within the conjugated heptazine backbone enables polymeric carbon nitrides the dual ability of light absorption and charge storage. However, the storage capacity has still been plagued by the severe recombination of photoinduced electrons and holes. Carbon-rich polymeric carbon nitrides (CPCN) with the conjugated backbone combining heptazine motifs and individual aromatic nucleus have tunable energy band structure. Herein, in order to enhance the photo-rechargeable capacity, we present a type-II homojunction constructed by two CPCN monolayer materials with different bandgaps and band-edges to build the band bending for charge separation. The desirable hole-extraction route for the CPCN photo-rechargeable solar cell is revealed and a remarkable high record of photo-charging capacity of 486 C g−1 is achieved. The microstructure of the CPCN materials are characterized by XPS, NMR, UPS and UV-Vis. The photoelectrochemical properties of the CPCN monolayer and homojunction photoelectrodes are investigated using cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS) and Mott-Schottky method.

Multiple Phase Stepping Generation in Alkali Metal Atoms: A Comparative Theoretical Study

We theoretically demonstrated optical phase switches in light storage-like experiments. Typical light storage (LS) and retrieval experiments consist of the probe field in the probe channel with writing and reading fields across the drive branch, as well as its recovery. The probe and first drive pulses as the standard electromagnetically induced transparency (EIT) effect of storing light are used in the proposed scheme for the atomic excitations. A train of probe pulses is used after a short storage period to induce Raman gain in the drive channel. The proposed scheme was applied to alkali-metal atoms such as 23Na, 87Rb, and 39K vapours. Spatiotemporal phase variations for generated drive pulses were found to shape in the form of discrete phase distributions. The proposed approach in the process of obtaining phase discrete distributions for different irradiation intensities was tested. For weak fields, the discrete distributions were distinct as a result of the differences in the upper hyperfine structure (hf) and the atomic relaxations. However, for moderate fields, the discrete phase distributions are smeared by the atomic relaxations.

Effect of Long-Term Storage in Light and Dark at Room Temperature on Physicochemical Characteristics of Some Vegetable Oils

Effect of Long-Term Storage in Light and Dark at Room Temperature on Physicochemical Characteristics of Some Vegetable Oils

Controlling persistent luminescence in nanocrystalline phosphors.

Persistent luminescent phosphors can store light energy in advance and release it with a long-lasting afterglow emission. With their ability to eliminate in situ excitation and store energy for long periods of time, they are promising for broad applications, including background-free bioimaging, high-resolution radiography, conformal electronics imaging and multilevel encryption. This Review provides an overview of various strategies for trap manipulation in persistent luminescent nanomaterials. We highlight key examples in the design and preparation of nanomaterials with tunable persistent luminescence, particularly in the near-infrared range. In subsequent sections, we cover the most current developments and trends concerning the use of these nanomaterials in biological applications. Moreover, we assess their advantages and disadvantages compared with conventional luminescent materials for biological applications. We also discuss future research directions and challenges, such as insufficient brightness at the single-particle level, and possible solutions to these challenges.

Extraction, antioxidant activity, and hydrogel formulation of marine Cladophora glomerata

In this study, the extraction of marine algae Cladophora glomerata using acetone, methanol, and ethanol solvents was investigated. The extraction yield was in the range of 3.47–4.20 % with a total phenolic content of 2.21–3.40 mg gallic acid equivalent per gram dried weight sample (mg GAE/g DW), and an antioxidant activity IC50 of 0.15–0.39 mg/mL. High chlorophyll and carotenoid contents were observed in all extracts, ranging from 138.44 to 200.79 μg/g DW, 119.05–308.43 μg/g DW, and 15.11–43.45 mg/g DW for chlorophylls a, b, and total carotenoids, respectively. The ethanol extract was selected for further investigation because it has high extraction efficiency and is already used in pharmaceutical preparations.The gas chromatography-mass spectroscopy (GC–MS) profile of the ethanol extract showed palmitic acid (21.4 %), 2,4-di-tert-butylphenol (14.5 %), and dibutyl phthalate (7.7 %) as major compounds. The extract at concentrations of 7.8125–125 μg/mL did not affect the viability of lung fibroblast cells (MRC-5). However, at the concentrations of 250–1000 μg/mL, the extract significantly decreased cell viability. A topical C. glomerata extract hydrogel was developed. The hydrogel had a homogenous texture; was stable in terms of appearance, pH, and spreadability in a variety of low and high temperatures; light and dark storage conditions, and it retained its antioxidant activity after storage. These findings showed that C. glomerata extract hydrogels could potentially be developed as a skin care product on a manufacturing scale.

Recyclable Time–Temperature Indicator Enabled by Light Storage in Particles

AbstractTime–temperature indicator (TTI) technologies allow for nondestructive and real‐time quality management of perishable products during the entire transport–storage process, which provides an important guarantee for the product safety of end users. However, the existing TTI technologies still have shortcomings in recyclability, sensitivity, and environmental tolerance, limiting their widespread applications. Herein, a new TTI route based on the light storage effect in persistent luminescent (PersL) materials is proposed. Such TTI is designed on account of the principle that the release rate of light‐induced trapped carriers in PersL materials is closely dependent on the storage time and temperature, enabling to establish a correlation between the number of residual carriers and the freshness of perishable products. Taking KZnF3:Mn2+ as a model material, the light‐storage‐based TTI technology shows excellent recyclability, reliability, and environmental stability. This work reveals great potentials of PersL phosphors as information recording materials in advanced TTI application and next‐generation biological detection technology.

Effects of Natural Diffused Light Storage on Highland Seed Potatoes and Subsequent Field Performance in Lowland

Effects of Natural Diffused Light Storage on Highland Seed Potatoes and Subsequent Field Performance in Lowland

Terahertz Electromagnetically Induced Transparency with Electric-Field-Coupled Inductor-Capacitor Resonators on LCP Substrate

Electromagnetically induced transparency (EIT) metamaterials (MTMs) based on the bright-dark mode theory have gained great interest in slow light, sensing, and energy storage in recent years. Typically, various split ring resonators with magnetic response have been proposed as dark resonators in EIT MTMs. Here, we have employed a cut-wire (CW) and two electric-field-coupled inductor-capacitor (ELC) resonators with a pure electrical response on a liquid crystal polymer (LCP) substrate with a low loss tangent to fulfill the EIT effect in the terahertz (THz) region. The former works as the bright mode, and the latter functions as the dark mode. The EIT phenomenon results from the destructive interference between these two modes, which can be verified by numerical simulation and near field distribution. In addition, a Lorentz oscillator model was studied to quantitatively analyze the relationship between the coupling strength and the coupling distance. As a demonstration, an EIT MTM device with 5000 units was fabricated and characterized, which showed a transmission window with a peak value of 0.75 at 0.414 THz. This work may inspire new multifunctional EIT MTMs, especially the flexible applications at THz frequencies.