Radiative cooling (RC) is a passive cooling technique that operates without requiring energy input, which can effectively alleviate the strain on car cooling systems caused by high temperatures during summer, particularly in the context of the widespread adoption of electric vehicles. A flexible transparent double-layer radiative cooling film based on Polyvinylidene Fluoride (PVDF) and Thermoplastic Polyurethane (TPU) as car protective film is proposed in this work. The transparency of the PVDF-TPU (PT) film reaches 71 %, preserving the aesthetic appearance of the vehicle, while exhibiting an emissivity rate of 98 %. The outdoor cooling experiments conducted on a clear summer day in China Three Gorges University (Yichang city) resulted in a significant subambient temperature reduction of 17.3 degrees C. Furthermore, the flexible PT double-layer film can be tailored and applied to precisely conform to the unique contours of each vehicle, effectively protecting its paint from potential scratches caused by external elements such as sand or branches.

Despite rapid advances in the power conversion efficiency (PCE) of perovskite solar cells (PSCs) over the past decade, notorious optical and non-radiative recombination losses still hinder the performance from reaching the Shockley-Queisser (S-Q) limit. Here, we introduce a multifunctional tin oxide (SnO2) electron transport layer with periodic nanoconvex (NC) morphology, constructed through histidine hydrochloride hydrate (His-HClH2O)-induced colloidal self-assembly. The nanostructure enhances broadband light harvesting through Mie scattering and resonant coupling, as confirmed by finite-difference time-domain (FDTD) simulations. Concurrently, amino and carboxyl groups from his interact with uncoordinated ions at the SnO2/perovskite interface, suppressing trap density and optimizing energy band alignment. Ultimately, the best-performing device achieves a PCE of 26.51% (certified 26.11%) and retains 87% of its initial efficiency after continuous maximum power point tracking for 1200 h. Scaled-up devices also exhibit impressive performance, with champion PCEs of 25.96% and 23.67% for 1.0 cm2 cell and 17.1 cm2 mini-module, respectively.

The rising temperature of ground objects under solar irradiation has led people to an increasing dependence on cooling methods that consume huge energy such as air conditioners and fans. Building windows and vehicle windows also have caused huge losses of energy due to allowing sunlight to enter. Therefore, it is of great significance to simultaneously endow outdoor application materials with radiative cooling capacity and adjustable light transmittance. In this study, hydroxypropyl cellulose (HPC) hydrogel radiative cooler was developed with high emissivity (0.96) and excellent visible light modulation ability (Delta Tlum) with a high maximum transmittance (91.2 %) and Delta Tlum (83.8 %). An ultra-low phase change temperature of 45 degrees C is achieved to meet insulation requirements and energy saving targets under hot climatic conditions. In the outdoor experiment, the HPC hydrogel radiative cooler can reduce the temperature by approximately 5 degrees C and 15 degrees C compared with the ordinary glass and aluminum sheet. The HPC hydrogel after phase transformation shows excellent cooling effect on different substrates such as glass and aluminum sheet. After 20 heating/cooling cycles and one month of exposure, the transmittance and Delta Tlum of the cooler have no obvious changes. The significant temperature rise suppression effect and transmittance adjustable performance of the HPC hydrogel radiative cooler opens up a promising avenue for application.

Passive radiative cooling technology, reducing space temperature by reflecting sunlight and emitting thermal to the outer space through the atmosphere transparent window, is a potential strategy for energy saving and sustainable development. In this work, a flexible-porous-array cellulose acetate (FPA-CA) film with high reflectivity (0.92) in the wavelength range of sunlight (0.2-2.5 mu m) and high emissivity (0.95) in the wavelength range of 3 similar to 20 mu m was fabricated through phase separation method. Owing to the designed porous structure and superior optical properties, the back surface of FPA-CA film achieved maximum cooling temperatures of 17.3 degrees C, 7.8 degrees Crelative to the structure-smooth cellulose acetate (SS-CA) and the FPA-CA film inside space, under solar intensity of 820W/m(2), and 7.25 degrees C,13.5 degrees C relative to the commercial white paint (CWP) and substrate made of wood material under solar intensity of 710 W/m(2), 800W/m(2), respectively. The appearance and radiation cooling performance of the prepared coating are both nearly no changed after one year shelved in atmospheric environment. The calculated maximum net cooling power of the FPA-CA film can be achieved 125.09Wm(-2). Owing to the fabrication process of the FPA-CA film is simple and suitable for large-scale production, it is extended a novel strategy for developed of radiative cooling and will hold a potential application in electrical equipment, building exterior wall or fabric which needs cooling surrounding.

Passive radiative cooling (PRC) is a zero-energy-consumption technology that reflects sunlight and radiates heat to cold outer space. In this work, a porous poly(vinylidene fluoride)-poly(methyl methacrylate) (PVDF-PMMA) composite film is fabricated by decorating zinc-imidazolate metal-organic framework (MOF) (ZIF-8) particles obtained by phase inversion. Due to the competent scattering via the coral-like hierarchical structures and the vibration excitations of specific functional groups, the prepared film exhibits good solar reflectance (92.6%) and intermediate infrared emittance (99.1%), with an average sub-ambient cooling of 10.4 degrees C under a solar radiation intensity of 0.6 AM1.5. Additionally, poly(vinylidene fluoride) has a low surface energy, while the ZIF-8 particles and coral-like hierarchical structures enhance the surface roughness, endowing the surface with significant superhydrophobicity characterized by a water contact angle (WCA) of 157.5 degrees and a sliding angle (SA) of 2 degrees. These films exhibit excellent antibacterial properties. When the content of ZIF-8 particles in the film is 300 mgL-1, the antibacterial rate reaches 100% after 1 h of treatment. Thus, the ZIF-8 porous poly(vinylidene fluoride)-poly(methyl methacrylate) composite (ZPPP) film has potential application prospects in areas with high health and environmental requirements, such as cold chain transportation and public spaces.

Thin film perovskite solar cells (PSCs) have insufficient light utilization due to thickness limita-tion. Structural design of thin film PSCs can effectively enhance the property of light trapping and thereby improve the photocurrent density. In this work, both the thickness of perovskite layer and front Indium Tin Oxides (ITO) layer for classical PSCs was firstly optimized. 22.4% of light ab-sorption enhancement can be achieved. Then, we proposed four different types of multilayer conformal structures PSCs consisting of hemisphere, cylinder, inverted pyramid and cone struc-tures. Compared with the planner PSCs, the optimized hemispherical multilayer conformal structure (HMCS) PSCs can further enhance the light absorption by 12.3% and obtain the highest photocurrent density of 23.82 mA/cm  2. The photonic interaction between the structure and incident wavelength is examined and discussed. The presented method and multilayer conformal structures can be used to design the light absorption enhancement for a variety of PSCs.

Daytime radiative cooling as passive cooling technology with zero consumption of energy and zero emission of green gas, has recently attracted tremendous interest by reflecting sunlight and radiating heat to the ultracold outer space. Some progress has been made, while it still remains big challenge in transparent and radiation cooling double characteristics radiative coolers. Here, we propose a spectrally selective coating based on tri-cyclodecane dimethanol diacrylate (DCPDA) monomer. Acid-and basic-proof coating are fabricated with simple and scalable blade and spray coating methods at room temperature. The coated glass displays a transmissivity around 90% in visible wavelengths from 400 nm to 800 nm and a thermal emissivity above 95% over atmo-spheric window (8-13 mu m). In clear summer in Yichang city with no wind, outdoor cooling tests demonstrated that realizes sub-ambient cooling of 18.6 degrees C during midday when applied on the aluminum (Al) sheets substrate. Featured with scalability, durability, and superior cooling performance make the film shows promising potentials for transparent radiative cooling applications.

Passive daytime radiative cooling (PDRC) technology can make objects cooling down without energy consumption by radiating out heat through the atmospheric transparent window (ATW, 8-13 mu m) and simultaneously reflect incident sunlight to avoid heated. In this work, a flexible radiative cooling film (FRCF) was fabricated by embedding zirconium dioxide (ZrO2) particles into polydimethylsiloxane (PDMS). It exhibited a high emissivity over 0.95 in ATW and a high reflectance beyond 0.92 in range of visible light. It achieved better cooling performances and yields an average temperature drop of 16.1 degrees C compared to the air around the film under the solar intensity of 735 W/m2. Because of its good cooling performance, great flexibility and acid resistance, this FRCF will have a wide application of radiative cooling in buildings and equipment.

Passive daytime radiative cooling (PDRC) technique is desirable for outdoor application as it can cool objects without energy consumption. In this work, a polydimethylsiloxane (PDMS) film incorporated with Kaolin particles was fabricated by a simple and low-cost method. Integrating with high sunlight reflectance and great thermal emissivity, the sample displayed a remarkable PDRC property by yielding an average temperature drop of 12.8celcius compared to the sub-ambient temperature. Additionally, the superhydrophobicity of the sample enabled the surface of the sample free-contamination after water rinse. The superhydrophobic properties can be maintained even after 60 days of UV light continuous exposure.

Passive daytime radiative cooling (PDRC) is a technology without requiring additional energy that cools objects by reflecting sunlight and radiating heat into outer space. However, the design process of PDRC films is relatively complicated or costly, which is not conducive to large-scale fabrication. For this, we fabricated a flexibly hier-archical porous polydimethylsiloxane (PDMS) radiative cooling film, which is simple and fast to fabricate and can be used for efficient large-scale production. It can reach the average emissivity of 0.95 in the transparent atmospheric window (8-13 mu m). The average reflectance is above 0.7 in the solar wavelength band (0.3-2.5 mu m), which is nearly 9 times of the non-porous structure. Thus, the porous PDMS films realize excellent sub-ambient temperature drop of 14.9 degrees C at the solar intensity of 910 W/m2.

Herein, a superhydrophobic cement (SC) with a water contact angle of 154 degrees and a water sliding angle of 8 degrees was fabricated by a convenient and green method. The salt resistance tests demonstrated that SC had a structural water-repellent ability with approximately 7.5 times lower cumulative water absorption rate and 8 times lower cumulative NaCl absorption rate than ordinary cement (OC). The compression and flexural tests revealed that the SC possessed good mechanical properties with comparable compressive and flexural strengths relative to the OC. Additionally, the SC surface still maintained superhydrophobicity after 200 cycles of tests, which also indicated the SC had excellent mechanical robustness.

The accurate bandgap prediction of perovskites has great significance for solar cell devices. Although density functional theory can be used for the calculations of material bandgaps, this method requires rich material calculation knowledge, and there are often some questions about whether the results are consistent with actual experimental results or not. To address this, the present work adopts machine learning (ML) to predict bandgaps of perovskites, where we collect 227 sets of experimental bandgap data of perovskites from the latest 1254 publications, to establish and identify 4 models from 24 kinds of ML models. The results of the models achieve high accuracy with root mean square error (RMSE) of down to 0.55 and meanwhile, the pearson correlation coefficient of up to 99%. In addition, our ML models give the effect of each chemical composition constituting the ABX3-type perovskites on the bandgaps by using the SHAP value, and they can be well explained in physics. These results all show the powerful potential of machine learning to fast and accurately predicate the bandgaps of perovskite for solar cell devices.

Characterizing the electrical parameters of perovskite solar cells (PSCs) usually requires a lot of time to fabricate complete devices. Here, machine learning (ML) is used to reduce the device fabrication process and predict the electrical performance of PSCs. Using ML algorithms and 814 valid data cleaned from 2735 peer‐reviewed publications, ML prediction models are built for bandgap, conduction band minimum, valence band maximum of perovskites, and electrical parameters of PSCs. These prediction models have excellent accuracy, and the root mean square error of the prediction models for bandgap and power conversion efficiency (PCE) reaches 0.064 eV and 1.58%, respectively. Among the many factors that affect the performance of PSCs, those factors play a major role in the lack of comprehensive explanation. Through the prediction model of electrical parameters and Shapley Additive explanations theory, the factors affecting the PCE of PSCs are explained and analyzed. It can not only verify the objective physical laws from the perspective of ML, but also conclude that among the 13 features, the content of formamidinium/NH 2 CHNH 2 + plays the most important role in improving the PCE of PSCs. These results show that ML has great application possibilities in the PSC field.

Thin crystalline silicon passivated emitter and rear cell (PERC) solar cells are a very prospective technology for next-phase photovoltaic development due to the potential of high cost effectiveness. The reduction of silicon wafer thickness can significantly save the costs, but there is a loss of cell efficiency if cell design is not conducted. For the thinned 100 gm-thickness PERC solar cells without design, the efficiency loss is pronounced from commercial 180 gm-thickness. In this paper, we have designed and optimized SiO2/SiNx/SiNx/SiOx thin films (here two SiNx layers have different refractive index) on the front surface and SiNx/SiOx thin films on the back surface for the standard front single-sided textured PERC cells. Based on this, we further design and investigate the case of double-sided textured PERC solar cells. Compared with the reference cell, the present designs can lead to the short-circuit current density increase by 0.6 mA/cm2 and the open-circuit voltage enhancement by 10 mV for the front textured case, which causes the efficiency gain of 0.7% from 21.6% to 22.3%. For the double-sided textured cells, the efficiency has an extra increase of 0.6% from 22.3% to 22.9%. Finally, we have constructed the efficiency prediction model by using the multilayer perceptron algorithm in machine learning. It is found from the SHAP values that a significant effect of the front SiNx thickness is observed to predict the performance of the PERC cells.

Passive radiative cooling is a spontaneous pattern of reflecting sunlight and radiating heat into the cold outer space through transparent atmosphere windows. In this work, an ordered-porous-array polymethyl methacrylate (OPA-PMMA) film with the properties of excellent radiative cooling is designed and studied. An ultra-high emissivity of 98.4% in the mid-infrared region (3-25 μm) and a good solar reflectance of 85% in the ultraviolet and near-infrared solar spectra (0.2-2.5 μm) were achieved. The surface temperature of the OPA-PMMA film is 16 °C lower than that of the smooth-surface PMMA films and is 8.6 °C lower than that of the commercial white paint in the outdoor test. The structure of the OPA plays an important role in improving solar reflectivity and emissivity. The films are fabricated using a one-step low-cost process that can be applied for large-scale production. It is vital for promoting radiative cooling as a viable energy technology for buildings, fabric, or equipment that need a cooling environment.

Passive Radiative cooling as a no energy consumption cooling method has been turned out to be a broad application potential. Common commercial crystalline silicon (c-Si) solar cell arrays suffer working efficiency loss due to incident light loss and heating, which were attractive to wide research. In this work, polydimethylsiloxane (PDMS) mixed with silica particles difunctional radiative cooler used for crystalline silicon solar cell is proposed. It takes place of glass encapsulant cover efficiently realized both high performance antireflective and radiative cooling. Through theoretical calculations, designed radiative cooler exhibited 94% of emissivity in radiative cooling wave band and 93.4% of transmittance in crystalline silicon solar responding wavelengths. The radiative cooler effect leads to a significant temperature decrease of a bare c-Si solar cell. A 9.5C decline is achieved and a 4.28% of operating efficiency loss was avoid. The design thought of high-quality solar cell radiative cooler in this work may have great application potential in the future.

Mechanically robust superhydrophobic (SHP) and icephobic performances are highly needed for an anti-icing surface in practical applications. Here, a SHP coating is prepared on the aluminium (Al) substrate using hydrothermal reaction and subsequent modification of hexadecyltrimethoxysilane, showing a water contact angle larger than 158° and a sliding angle (SA) less than 5°. This SHP coating displays a robust hydrophobic performance in acidic or alkaline solutions, after sand abrasion and consecutive icing/deicing cycles. It largely reduces ice adhesive strength and delays starting icing time on Al. Therefore, this work may shine some light in engineering aluminium-based materials to avoid ice accumulation.

Superhydrophobic (SHP) coatings have been reported with many promising applications using various nano-micro structures with surfactants of low surface energies. However, many SHP coatings have poor durability, largely limiting their practical importance. In this study, a durable SHP coating is demonstrated with a novel veil-over-sprout micro-nano structure of silica nano particles (SNP) and poly(methyl methacrylate) (PMMA). This coating displays a large water contact angle (WCA) of 168.0° and a small sliding angle (SA) of less than 1.0°. Excellent abrasion resistance is demonstrated with excellent superhydrophobicity (WCA = 159.0°) after consecutive tests with sandpaper, high-density water flow and fine sand impact. An excellent self-healing function has been achieved with this SHP coating after stored at room temperature, recovering its remarkable superhydrophobicity. Outstanding resistance against ice formation is exhibited with the starting-freezing time at −20 ℃ three times longer than uncoated surface. Strong resistance to acid and base attacks is observed even after a week of immersion in highly acidic and alkaline environments (pH 1.0–14.0), without much degradation of SHP performance. Efficiency of up to 99.9% is demonstrated in corrosion protection in a solution with pH = 10.0 to extend the life of the metal. In addition, remarkable SHP durability is demonstrated after long-term outdoor exposure. Therefore, this work has shown off a promising methods for SHP coatings towards future practical applications.

An effective superhydrophobic and self-healing coating is fabricated on building materials. This coating can restore its properties at room temperature after being damaged by rubber or acid. The coating can not only be directly applied on different substrates, but also be used for anti-corrosion. The corrosion current of the coated iron plate is reduced by 57.1%, and the corrosion potential is increased by 3.9%. (C) 2020 Elsevier B.V. All rights reserved.

A design of ultrathin crystalline silicon solar cell with Si 3 N 4 circular truncated cone holes (CTCs) arrays on the top is proposed. In this article, we perform an optical simulation of the structure. The finite-difference time-domain method is used to calculate the optical absorption of different periods, radius of top and bottom circles and depth of Si 3 N 4 CTCs. The short-circuit current density generated by the optimized cells (30.17 mA/cm 2 ) is 32.44% more than the value gained by control group (with flat Si 3 N 4 ). Then adding a layer of back silver to allow us to better analyze optical absorption. Later, we simulate the optimization of the same configuration of different silicon thicknesses and find that our structure does enhance the light absorption. This work uses a combined path towards achieving higher photocurrent ultrathin crystalline silicon solar cells by constructing the texture of anti-reflection coating .