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This study investigates the effect of continuous blue light (CBL) treatment on quality-related metabolites, focusing on ascorbic acid (AsA) accumulation in hydroponically grown Eruca vesicaria (L.). Plants were subjected to CBL treatment, consisting of 24-h exposure to constant-intensity blue light (48 µmol m-2 s-1) and 12-h exposure to the remaining spectrum (192 µmol m-2 s-1). The activities of key enzymes in AsA biosynthesis and recycling were analyzed, including L-galactono-1,4-lactone dehydrogenase (GalLDh), monodehydroascorbate reductase (MDhAR), dehydroascorbate reductase (DhAR), and ascorbate peroxidase (APX). The results showed a significant increase in AsA accumulation of 65.9% during the "day" and 69.1% during the "night" phases under CBL compared to controls. GalLDh activity increased by 20% during the "day phase" in CBL-treated plants. APX activity also rose significantly under CBL conditions, by 101% during the "day" and 75.6% during the "night". However, this did not affect dehydroascorbic acid levels or the activities of MDhAR and DhAR. These findings highlight the potential of tailored light treatments to enhance the nutraceutical content of horticultural species, offering valuable insights for sustainably improving food quality in controlled-environment agriculture (CEA) systems and understanding the roles of blue light in ascorbic acid biosynthesis.

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The conjugation of terminal ammonium salt groups with perovskite surfaces is a frequently employed technique that aims to enhance the overall performance of perovskite materials, encompassing both bulk and surface properties. Particularly, it exhibits heightened efficacy when applied to surface modification, due to its ability to mitigate defect accumulation and facilitate facile binding with the receptive sites inherent to the perovskite structure. However, the interaction of the bulk ammonium group with PbI2 has the potential to form a low-dimensional phase of perovskite, which may obstruct carrier extraction at the interface. Therefore, the surface passivators (MeO-PFACl) are designed through intramolecular potential manipulation. The combinations of the electron-donating methoxy group and π-π conjugation of the phenyl ring reduce the local potential at the reactive site of formamidinium group, making it less likely to form a low-dimension phase with perovskite. This surface passivation strategy effectively suppresses the surface nonradiative recombination and promotes the interface carrier extraction. The devices treated with MeO-PFACl have demonstrated exceptional performance, achieving a peak power conversion efficiency (PCE) of 25.88%, with an average PCE of 25.37%. These works offer a novel principle for enhancing both the efficiency and stability of PSCs using ammonium-incorporated molecules without the induction of an additional phase layer.

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This work aims to understand how nanocellulose (NC) processing can modify the key characteristics of NC films to align with the main requirements for high-performance optoelectronics. The performance of these devices relies heavily on the light transmittance of the substrate, which serves as a mechanical support and optimizes light interactions with the photoactive component. Critical variables that determine the optical and mechanical properties of the films include the morphology of cellulose nanofibrils (CNF), as well as the concentration and turbidity of the respective aqueous suspensions. This study demonstrates that achieving high transparency was possible by reducing the grammage and adjusting the drying temperature through hot pressing. Furthermore, the use of modified CNF, specifically carboxylated CNF, resulted in more transparent films due to a higher nanosized fraction and lower turbidity. The mechanical properties of the films depended on their structure, homogeneity (spatial uniformity of local grammage), and electrokinetic factors, such as the presence of electrostatic charges on CNF. Additionally, we investigated the angle-dependent transmittance of the CNF films, since solar devices usually operate under indirect light. This work demonstrates the importance of a systematic approach to the optimization of cellulose films, providing valuable insight into the optoelectronic field.

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The surface morphologies of polymer films have been used to improve the performance or enable new applications of films, such as controllable adhesion, shape morphing and light management. However, complicated and destructive methods were applied to produce surface morphologies on chitosan (CS) film. To overcome this challenge, we report an evaporation-induced self-assembly to form the tunable morphologies on the surface of short-chain chitosan film by varying the evaporation rates that influence the aggregation behavior of polymer chains between order and disorder. It enables the simple, tunable and scalable fabrication of surface morphologies on CS film (CS solution concentration: 2 wt%, drying from room temperature (RT) to 80 °C) that provides controllable haze (3-74 %) and high transmittance (>85 %) for the production of hazy and transparent window coatings. This simple approach to producing tunable surface morphologies could inspire the synthesis of multifunctional polymer films with different surface structures, whose applications can be extended to cell culture interfaces, flexible bioelectronic and optoelectronic devices.

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The increased use and expansion of biomass applications offer a viable approach to diminish reliance on petroleum-derived resources and promote carbon neutrality. Cellulose, being the most abundant natural polymer on Earth, has garnered considerable attention. This study introduces a straightforward method to fabricate a cellulose-based multifunctional composite film designed for efficient light management, specifically featuring flame retardant and thermal-healing capabilities. The film incorporates a microfibrillated cellulose (MFC) matrix with functional components, namely benzoxazine resin (BR) and 2-hydroxyethyl methacrylate phosphate (HEMAP). Utilizing dynamic covalent crosslinking, the composite films exhibit satisfactory self-healing properties. The combined effects of BR and HEMAP contribute to the effective flame retardancy of the composite film. Furthermore, the resulting film shields ultraviolet and blue light, offering comfortable interior lighting by mitigating harsh light and extending light propagation. The film also demonstrates favorable water resistance and high tensile strength. The exceptional multifunctional properties, coupled with its safety and extended service life, position it as a potential optical management film for smart building materials.

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The importance of light management for perovskite solar cells (PSCs) has recently been emphasized because their power conversion efficiency approaches their theoretical thermodynamic limits. Among optical strategies, anti-reflection (AR) coating is the most widely used method to reduce reflectance loss and thus increase light-harvesting efficiency. Monolayer MgF2is a well-known AR material because of its optimal refractive index, simple fabrication process, and physical and chemical durabilities. Nevertheless, quantitative estimates of the improvement achieved by the MgF2AR layer are lacking. In this study, we conducted theoretical and experimental evaluations to assess the AR effect of MgF2on the performance of formamidinium lead-triiodide PSCs. A sinusoidal tendency to enhance the short-circuit current density (JSC) was observed depending on the thickness, which was attributed to the interference of the incident light. A transfer matrix method-based simulation was conducted to calculate the optical losses, demonstrating the critical impact of reflectance loss on theJSCimprovement. The predictedJSCs values, depending on the perovskite thickness and the incident angle, are also presented. The combined use of experimental and theoretical approaches offers notable advantages, including accurate interpretation of photocurrent generation, detailed optical analysis of the experimental results, and device performance predictions under unexplored conditions.

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The ever-increasing concern for energy shortages and greenhouse effect has triggered the development of sustainable green technologies. Microalgae have received more attention due to the characteristics of biofuel production and CO2 fixation. From the perspective of autotrophic growth, the optimization of light quality has the potential to promote biomass production and bio-component accumulation in microalgae at low cost. In this study, bibliometric analysis was used to describe the basic features, identify the hotspots, and predict future trends of the research related to the light quality on microalgae cultivation. In addition, a mini-review referring to regulation methods of light quality was provided to optimize the framework of research. Results demonstrated that China has the greatest interest in this area. The destination of most research was to obtain biofuels and high-value-added products. Both blue and red lights were identified as the crucial spectrums for microalgae cultivation. However, sunlight is the most affordable light resource, which could not be fully utilized by microalgae through the photosynthetic process. Hence, some regulation approaches (e.g., dyes, plasmonic scattering, and carbon-based quantum dots) are proposed to increase the proportion of beneficial spectrum for enhancement of photosynthetic efficiency. In summary, this review introduces state-of-the-art research and provides theoretical guidance for light quality optimization in microalgae cultivation to obtain more benefits.

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In this study, cellulose composite films (CCFs) were fabricated through controllable dissolution and regeneration process of cellulose with the addition of polyvinyl alcohol (PVA). The competition of hydrogen bond site between cellulose and PVA led to partial dissolution of cellulose and maintained morphology of micron fibers with width range from 14.55 to 16.16 µm, which served as in-situ visible light scatterers. With this unique micron structure, the obtained CCF exhibited high transparency up to 90.5 % at 550 nm and ultrahigh haze up to 96 %. Interestingly, CCF could be used as hazy and flexible substrate, such as scattering lamp covers for indoor light management, anti-glare screen protectors and anti-reflection layers of solar cell devices. Among them, the efficiency of the solar cell device could be improved by 10.38 % with the help of a low-cost, excellent-performance CCF.

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Herein, we develop a strategy of matched spectral and temporal light management to improve photosynthetic efficiency by co-assembling natural thylakoid membrane (TM) with artificial long afterglow particle (LAP). To be specific, LAP with excellent stability and biocompatibility possesses the capabilities of light conversion and storage, optically-matched with the absorption of TM. These favorable features permit LAP as an additional well-functioned light source of photosynthesis performed by TM. As a consequence, enhanced photosynthesis is achieved after co-assembly, compared with pure TM. Under light, the rates of electron transfer, oxygen yield and adenosine triphosphate (ATP) production in this biohybrid architecture are boosted owing to down-conversion fluorescence emission from LAP. Under dark, persistent phosphorescence emission in charged LAP facilitates continual photosynthesis of TM, while that of pure TM almost stops immediately. This proof-of-concept work opens a new route to augment the photosynthetic efficiency of green plants by utilizing precise light-managed materials.

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Smart windows with tunable optical properties for energy-saving and privacy protection applications are receiving increasing attention. However, current studies of smart windows either involve the use of complex material preparation processes and complex device systems for window switching or continue to face several challenges, including low luminous transmittance, low luminous and solar modulation, and narrow wavelength range management problems. Here, we report a dual-responsive smart window that achieves solar light management in the range of 200-2500 nm. This smart window is fabricated by combining a reversible thermoresponsive hydrogel that acts as a thermochromic material with a ZnO/Ag/ZnO multilayer film that acts as a transparent heater. The as-prepared smart window can modulate solar light over a range from ultraviolet to infrared and achieves active responses to high-temperature weather, with passive responses being produced through electrical heating. The smart window shows high luminous transmittance (81.7%) and high luminous modulation (81.6%), together with an outstanding solar modulation performance (62.9%). In outdoor demonstrations, the as-prepared smart window exhibited a promising temperature regulation ability under strong solar irradiation. Therefore, the proposed smart window promises to provide a simple and effective energy management technology for buildings.

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Biodegradable cellulose films with excellent mechanical, optical, and functional properties have attracted considerable attention as promising alternatives to plastics for photoelectronic devices. In this work, mechanically ductile, flame-retardant cellulose films with tunable optical properties were prepared by simple mechanical disintegration of phosphorylated cellulose (PhC) fibers, vacuum filtration of as-prepared dispersions, and subsequent pressing of the wet PhC films to prepare dried films. When mechanical disintegration conditions were optimized, the resultant PhC films exhibited an average density, tensile strength, Young's modulus, tensile toughness, and folding resistance of 1.4 g/cm3, 150 MPa, 8.5 GPa, 8.2 MJ/m3, and 4580 times, respectively. The PhC film hazes were widely controllable from 9 % to 91 %, while they maintained high light transmittances (>90 %) at a 550-nm wavelength. The PhC films were used for light management of light-emitting diodes by controlling mechanical fibrillation conditions of the PhC fiber/water slurry, showing that the films effectively improved the luminescence uniformity of the devices.

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Light-management materials play a great significant role in efficient-energy buildings because they reduce indoor energy consumption by adjusting to natural sunlight, enhancing heat insulation, and creating comfortable indoor lighting. Here, we fabricated an ecofriendly and sustainable lignocellulose-based light-management film via a facile homogenization and mechanical hot-pressing method without complicated treatment or toxic reagents. The resulting film exhibited a favorable ultraviolet (UV) blocking performance of 82.25% for UVA, high visible light transmittance, and high haze, with a desirable tensile strength of 197 MPa, which was significantly higher than those of most petroleum-based plastics. Accordingly, the film was further endowed with near-infrared absorption performance by spray-coating with lanthanum hexaboride (LaB6) nanoparticles─there were almost no adverse effects on its light transmittance or mechanical strength. Meanwhile, the high haze of the film implied that it met the requirement for privacy protection in smart buildings. The MFC/lignin/LaB6 composite film has potential applications in energy-saving buildings and optoelectronic devices.

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Light-management films made entirely from natural polymers with tunable haze properties are developed via a facile approach. A novel green method based simply on the blending of network cellulose (NC)/water suspension with alginate (CaAlg) aqueous solution is proposed. The unique NC suspension created by a controlled hydrolysis of microcrystalline cellulose acts as the scatterer media while alginate serves as the transparent host matrix. NC features isotropic intertwined network of nanofibers that contributes to light scattering and produces optical haze. The opaque but hazy NC is dispersed purposefully in the alginate film, where its original properties are preserved owing to its poor solubility in water. Additionally, the dispersion notably increases the roughness of the composite film surface and acts as a light scatterer. Eventually, composite CaAlg/NC film with high transparency (>94%) and customized haze (15-73%) at 550 cm-1 wavelength is fabricated. Herein, the transparent alginate is successfully combined with the hazy cellulose of uniformly distributed nanofibers by blending to fabricate transparent/hazy all-natural films. The fabricated films exhibit high transparency with tailored transmission haze. The film is highly fitting for large-scale production and adequate to meet different haze requirements to accommodate different applications such as privacy protection films and antiglare/antireflection coatings.

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Solution processing of highly performing photonic crystals has been a towering ambition for making them technologically relevant in applications requiring mass and large-area production. It would indeed represent a paradigm changer for the fabrication of sensors and for light management nanostructures meant for photonics and advanced photocatalytic systems. On the other hand, solution-processed structures often suffer from low dielectric contrast and poor optical quality or require complex deposition procedures due to the intrinsic properties of components treatable from solution. This work reports on a low-temperature sol-gel route between the alkoxides of Si and Ti and poly(acrylic acid), leading to stable polymer-inorganic hybrid materials with tunable refractive index and, in the case of titania hybrid, photoactive properties. Alternating thin films of the two hybrids allows planar photonic crystals with high optical quality and dielectric contrast as large as 0.64. Moreover, low-temperature treatments also allow coupling the titania hybrids with several temperature-sensitive materials including dielectric and semiconducting polymers to fabricate photonic structures. These findings open new perspectives in several fields; preliminary results demonstrate that the hybrid structures are suitable for sensing and the enhancement of the catalytic activity of photoactive media and light emission control.

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Transparent lignocellulose nanopaper (LNP) has been demonstrated to be a promising candidate light-management material for next-generation optical engineering applications. Similar to its role in plant cell walls, lignin serves as a vital functional component in LNP matrices. However, its intrinsic light absorption property renders LNP undesirable for a range of optical management systems. Here, a highly efficient, controllable and ecofriendly lignin modification strategy is developed for modulating the optical performance of LNPs by taking advantage of the beneficial synergistic effect of H2O2 and UV light in selectively eliminating lignin chromophores. The obtained lignin-modified LNP features not only a high visible light transmittance (89%) but also a high haze (90%) and excellent UV-shielding capacity, owing to the well-preserved lignin aromatic skeleton structures after lignin modification. Furthermore, patterning is easily achieved on hot-pressing-induced densified LNPs through a selective lignin modification approach, which endows LNPs with intriguing optical designability. Benefitting from the multifunctionality of lignin components for nanopaper matrices, patterned LNPs demonstrate outstanding water and thermal stability, barrier properties, durability and biodegradability, which are of great significance for practical applications. Furthermore, we demonstrate the great applicability of this optically designable and multifunctional LNP as a light-management material for energy efficient buildings by highlighting its attractive sun- and indoor- light managing effects, effective thermal insulation, as well as superior durability for long-term use. In combination with its efficient, ecofriendly and controllable production, this novel high-performing LNP holds great potential in many other applications that require light-management structural materials, such as optoelectronic and sensing devices.

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Sustainable materials are needed to mitigate against the increase in energy consumption resulting from population growth and urbanization. Here, we report fully biobased nanocomposite films and coatings that display efficient photothermal activity and selective absorption of ultraviolet (UV) radiation. The nanocomposites with 20 wt % of lignin nanoparticles (LNPs) embedded in a chitosan matrix displayed an efficient UV blocking of 97% at 400 nm along with solar energy-harvesting properties. The reflectance spectra of the nanocomposite films revealed the importance of well-dispersed nanoparticles in the matrix to achieve efficient UV-blocking properties. Finally, yet importantly, we demonstrate the nanocomposites with 20 wt % LNPs as photothermal glass coatings for passive cooling of indoor temperature by simply tailoring the coating thickness. Under simulated solar irradiation of 100 mW/cm2, the 20 µm coating achieved a 58% decrease in the temperature increment in comparison to the system with uncoated glass. These renewable nanocomposite films and coatings are highly promising sustainable solutions to facilitate indoor thermal management and improve human health and well-being.

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Slurries of semiconductor particles individually capable of unassisted light-driven water-splitting are modeled to have a promising path to low-cost solar hydrogen generation, but they have had poor efficiencies. Tandem microparticle systems are a clear direction to pursue to increase efficiency. However, light absorption must be carefully managed in a tandem to prevent current mismatch in the subcells, which presents a possible challenge for tandem microwire particles suspended in a liquid. In this work, a Ni-catalyzed Si/TiO2 tandem microwire slurry is used as a stand-in for an ideal bandgap combination to demonstrate proof-of-concept in situ alignment of unassisted water-splitting microwires with an external magnetic field. The Ni hydrogen evolution catalyst is selectively photodeposited at the exposed Si microwire core to serve as the cathode site as well as a handle for magnetic orientation. The frequency distribution of the suspended microwire orientation angles is determined as a function of magnetic field strength under dispersion with and without uplifting microbubbles. After magnetizing the Ni bulb, tandem microwires can be highly aligned in water under a magnetic field despite active dispersion from bubbling or convection.

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Windows are critically important components in building envelopes that have a significant effect on the integral energy budget. For energy saving, here we propose a novel design of hydrogel-glass which consists of a layer of hydrogel and a layer of normal glass. Compared with traditional glass, the hydrogel-glass possesses a higher level of visible light transmission, stronger near-infrared light blocking, and higher mid-infrared thermal emittance. With these properties, hydrogel-glass based windows can enhance indoor illumination and reduce the temperature, reducing energy use for both lighting and cooling. Energy savings ranging from 2.37 to 10.45 MJ/m2 per year can be achieved for typical school buildings located in different cities around the world according to our simulations. With broadband light management covering the visible and thermal infrared regions of the spectrum, hydrogel-glass shows great potential for application in energy-saving windows.

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Cellulosic substrates completely originating from biomass have gained increasing attention for utilization in photoelectric devices due to their biodegradability, sustainability, and renewability. Herein, a simple one-step strategy was used to fabricate transparent (84.2%-90% at 550 nm) all-cellulose composites (ACCs) with customized optical haze (14.7%-83.7% at 550 nm) from wood and bamboo pulp due to their variable solubility. Surface roughness, coagulation bath composition, and the size of the undissolved cellulose fibers contributed to optical haze regulation. Fabricated ACCs demonstrated water resistance, thermal stability, and good mechanical properties. Moreover, an enhancement in the power conversion efficiency of a perovskite solar cell was achieved by simple attachment. Compared with non-sustainable petroleum base materials, ACCs exhibit biodegradability and renewability, which makes the composites promising in large-scale production and various applications due to their tunable haze.

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Light-management (LM) films that can regulate transmitted light are significant to diverse fields, such as optoelectronics and energy-efficient buildings. However, for conventional LM films made from petroleum-based polymers, the nonbiodegradability and complicated fabrication process remain a challenge. Herein, we prepare sustainable lignocellulose-based films with excellent light-management capability by facile dissolution and regeneration of wood pulp and the corncob residue from xylitol production (CRXP). The obtained films exhibit high transparency (78%), high haze (61%), and especially remarkable UV-blocking performance (99.94% for UVB and 98.04% for UVA). They achieve consistent indoor light distribution and UV radiation shielding by light management for the application of smart buildings. Furthermore, by spray-coating with SiO2 nanoparticles to construct hierarchical networks, the films are endowed with a superhydrophobic surface with a self-cleaning function to mitigate dust accumulation. Our work provides novel insights into the conversion of lignocellulosic waste to desirable and sustainable functional materials.