Design of hierarchical nanohole for efficient broadband light absorption of MAPbI3 perovskite material based solar cell with thin absorber layer

Perovskite solar cell has the advantages of low dosage of toxic materials, flexibility and consumer-oriented, which has significant development potential. Nanophotonic structure shows superior performance to common geometrical structure in controlling light transfer, which can capture and trap light, and thus improving the light absorption while reducing its thickness. In this work, novel wavelength-sized hierarchical nanohole is devised toward maximum broadband light absorption. The hierarchical nanohole can excite quasi-guided modes to improve light absorption, the electric field distribution is shown and demonstrated. The proposed perovskite solar cells with hierarchical nanohole outperform a planar solar cell by 17% in JSCand outperform a perovskite solar cell with one nanohole reference by 6.7% in JSC. In addition, the effects of hierarchical nanohole geometry on performance of perovskite solar cell are investigated. Overall, this work provides a new design for the ultra-thin perovskite solar cell with high energy conversion efficiency

Density functional studies of probucol excited states and spectral properties

Probucol (PB) is a lipid-regulating agent with powerful antioxidant, anti-inflammatory and anti-atherogenic effects. In this paper, based on density functional theory (DFT), B3LYP/def2tzvp functional and basis set are used to optimize the structure of PB molecule, and the vibration attribution analysis is carried out. On the basis of optimization, the first 40 excited states of molecule in anhydrous ethanol were calculated by time-density functional theory (TD-DFT). Then UV spectrum and electron–hole diagrams are drawn to analyze the excited state properties. Finally, the antioxidant mechanism of PB was theoretically analyzed by predicting the active site of PB molecule. This study has two purposes: first, to verify the experimental spectra, and second, to provide basic data for the properties of PB molecule, and provide theoretical reference for its antioxidant mechanism in clinical medicine, as well as antioxidant detection in food and care products

Efficient radiative cooling coating with biomimetic human skin wrinkle structure

Daytime radiative cooling is an energy-free pathway to achieve cooling performance. Current radiative cooling materials with periodic photonic structures are facing a huge challenge in terms of scale expansion owing to complex preparation technology and high cost. Herein, we proposed the idea of using biomimetic wrinkle structure combined with optimized particles to achieve the efficient optical property regulation of both the solar band and “atmospheric window” band. On this basis, a large-scale radiative cooling coating with the biomimetic structure of human skin natural wrinkle, comprising high concentrations of BaSO4 and SiO2 particles, was demonstrated. The coating with a thickness of ~100 µm reflected ~95% of solar irradiance, and the emissivity in the “atmospheric window” band was ~96%. At noontime (11:00–13:00), in a populous area located at sea level, the average effective cooling power of ~89.6 W/m2 was recorded, and the maximum sub-ambient temperature drop can reach 8.1 °C. An outdoor-building test conducted over a year showed that the maximum average indoor air temperature of the building painted with the coating was reduced by 6.2 °C and the maximum power-saving rate of air-conditioning exceeded 50%. Our work provided a new idea for designing, fabrication, and application of high-performance radiative cooling materials

Experimental study on the effects of light intensity on energy conversion efficiency of photo-thermo chemical synergetic catalytic water splitting

Hydrogen production from water using a catalyst and solar energy was an ideal future fuel source. In this study, an elaborate experimental test rig of hydrogen production from solar water splitting was designed and established with self- controlled temperature system. The effects of light intensity on the reaction rate of hydrogen production from solar water splitting were experimentally investigated with the consideration of optical losses, reaction temperature, and photocatalysts powder cluster. Besides, a revised expression of full-spectrum solar-to-hydrogen energy conversion efficiency with the consideration of optical losses was also put forward, which can be more accurate to evaluate the full-spectrum solar-to-hydrogen energy of photo-catalysts powders. The results indicated that optical losses of solar water splitting reactor increased with the increase of the incoming light intensity, and the hydrogen production rate increased linearly with the increase of effective light intensity even at higher light intensity region when the optical losses of solar water splitting reactor were considered

“Warm in Winter and Cool in Summer”: Scalable Biochameleon Inspired Temperature-Adaptive Coating with Easy Preparation and Construction

The highly reflective solar radiation of passive daytime radiative cooling (PDRC) increases heating energy consumption in the cold winter. Inspired by the temperature-adaptive skin color of chameleon, we efficiently combine temperature-adaptive solar absorption and PDRC technology to achieve “warm in winter and cool in summer”. The temperature-adaptive radiative cooling coating (TARCC) with color variability is designed and fabricated, achieving 41% visible light regulation capability. Comprehensive seasonal outdoor tests confirm the reliability of the TARCC: in summer, the TARCC exhibits high solar reflectance (∼93%) and atmospheric transmission window emittance (∼94%), resulting in a 6.5 K subambient temperature. In the winter, the TARCC’s dark color strongly absorbs solar radiation, resulting in a 4.3 K temperature rise. Compared with PDRC coatings, the TARCC can save up to 20% of annual energy in midlatitude regions and increase suitable human hours by 55%. With its low cost, easy preparation, and simple construction, the TARCC shows promise for achieving sustainable and comfortable indoor environments

Scalable Bio-Skin-Inspired Radiative Cooling Metafabric for Breaking Trade-Off between Optical Properties and Application Requirements

Passive daytime radiative cooling (PDRC) provides a zero-energy cooling technology to reduce the global fossil energy consumption and has already attracted tremendous interest. However, breaking the trade-off between the pursuit of ultrahigh dual-band (solar and atmospheric window) optical properties and the compatibility of multiple functional requirements by application is still a big challenge for PDRC. By introducing the photon slab-porous effect with strong sunlight backward scattering and inspired by human skin (epidermis and dermis) with recorded medical infrared emittance and multi-functions, we proposed an efficient dual-band optical property design strategy for PDRC. Through a simple and scalable dip dyeing process, the fabricated bio-skin-inspired PDRC metafabric exhibited superior dual-band optical properties, while both the solar reflectance and atmospheric window emittance can reach 97%. Outdoor tests demonstrated that the bio-PDRC metafabric achieved a maximum sub-ambient temperature drop of 12.6 °C in daytime. A human wearing a hat made of bio-PDRC metafabric can be 16.6 °C cooler than the one wearing a common hat. The bio-PDRC metafabric also exhibited superior performance of breathability, waterproofness, flexibility, strength, and durability to fulfill the multiple demands of personal thermal management, vents, and car covers