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Natural light-harvesting systems spatially organize densely packed chromophore aggregates using rigid protein scaffolds to achieve highly efficient, directed energy transfer. Here, we report a synthetic strategy using rigid DNA scaffolds to similarly program the spatial organization of densely packed, discrete clusters of cyanine dye aggregates with tunable absorption spectra and strongly coupled exciton dynamics present in natural light-harvesting systems. We first characterize the range of dye-aggregate sizes that can be templated spatially by A-tracts of B-form DNA while retaining coherent energy transfer. We then use structure-based modelling and quantum dynamics to guide the rational design of higher-order synthetic circuits consisting of multiple discrete dye aggregates within a DX-tile. These programmed circuits exhibit excitonic transport properties with prominent circular dichroism, superradiance, and fast delocalized exciton transfer, consistent with our quantum dynamics predictions. This bottom-up strategy offers a versatile approach to the rational design of strongly coupled excitonic circuits using spatially organized dye aggregates for use in coherent nanoscale energy transport, artificial light-harvesting, and nanophotonics.

Lighting is one of the systems that mostly consume electricity in commercial buildings. Therefore, improving its efficiency has the potential to reduce electricity consumption and emission of polluting gases. The objective of the present study was to assess an office lighting system retrofit of an existing building from the 1990s, verify the light levels in relation to standards of the Brazilian requirements, and to explore new systems with potential for luminous and energy improvement. The analyzes were carried out through computer simulations using the DIALux evo software, which allows the evaluation of artificial and natural illuminations simultaneously. The results indicated that the existing lighting system does not meet the average illuminance standard value for office environment. From simulations with new arrangements and types of luminaires and lamps, two more efficient lighting systems were designed. The first presented savings of 15.5% in lighting energy when replacing T12 fluorescent lamps with LED luminaires. The second system considered the use of natural light and was complemented by artificial lighting with the aid of a dimming system linked to the availability of daylight, and presented up to 67% less electric energy consumption when compared to the existing lighting system in the environments. Therefore, it was possible to propose actions to the existing lighting system retrofit and, thus, offer better visual comfort to users and at the same time save energy.

The matters of providing the requirements for workplace illumination are considered in the article. Attention is paid to the creation of natural lighting by the means of light conductors. The process of calculation of such structures is developed and presented. The authors have developed the programme, which determines coefficient of natural lightening according to the Lambert's law during the use of direct hollow tubular light conductors.

One of the most important aspects directly affecting a building’s performance is the design quality of the natural day-lighting. The present research evaluates the effectiveness of daylight in school buildings in the city of Baghdad. It aims to ascertain how the characteristics of building windows affect the quality of day-lighting, the objective of this exercise being to improve educational processes in schools by making improvements in relation to the aspect of provision of satisfactory day-lighting levels. A building simulation approach was adopted, and using Autodesk Revit 2018 (Insight plug-in), a daylight analysis was conducted under the aegis of the Building Information Modelling (BIM) technology. For the case study, we selected the modern design of a 24-classrooms school building, which is part of a plan for the construction of 1,000 Iraqi schools. Leadership in Environmental and Energy Design (LEED v4) simulation was conducted on the school building design to provide the results, which were measured and analysed according to LEED v4 standards. The results demonstrated that opening dimensions and direction have an essential impact on natural day-lighting. The research concluded that using BIM simulation tools enhances the design quality of the natural lighting in such a way that compliance with LEED v4 requirements is achieved. The present study will assist in identification and assessment of the problems concerned with natural lighting levels in Iraqi school buildings as well as resolving these at an early design stage.

Sunlight is an important thing that humans need to see, recognize and learn certain things in their environment. Sunlight helps humans carry out daily activities indoors. The aim of this research is to examine the intensity of natural lighting in houses in the coastal area of the case study RT 3, Pasar Bengkulu Village. This research is quantitative research by obtaining data from observations and Dialux software simulations. The measurement data will be compared with the lighting standards set out in SNI No. 03-2396-2001. From the simulation results, it was found that there were several rooms that had not reached natural lighting standards, namely, there were 3 rooms in house A, 2 rooms in house B and 3 rooms in house C. Simulation of the optimal light intensity value in house A in room 1 was 508 lux, room 2 is 217 lux and room 3 is 235 lux. At house BThe average value is 220 lux in room 1, the value is 230 lux in room 2, 229 lux in room 3, 235 lux in room 4 and room 5 gets a value of 213 lux. Meanwhile, in house C there is room 1 with a value of 141 lux, room 2 with a value of 197 lux, room 3 with a value of 163 lux, room 4 with a value of 292 lux and room 5 with a value of 242 lux.

The general purpose of natural lighting is to produce quality of light that is efficient and minimizes direct glare, and excess light level ratios. The natural light that enters through a window can come from several sources, namely direct sunlight, clear sky, clouds or reflections of the lower surface and surrounding buildings. The light from each source varies not only from the amount and heat it carries, but also on other qualities, such as colour, spread, and savings. Light is the most important part of human life, to get the right lighting in a space, the right lighting system is needed according to people needs so that visual comfort can be achieved. The library is an important means to support teaching and learning activities and in supporting the implementation of the Three Principles of Higher Education and, the library should be the centre of attention, especially in its lighting system. This study applies a quantitative analysis method with a descriptive approach where the measurement of natural lighting levels and calculation of the dimensions of shading devices are carried out as part of the research stage. The independent variables in this study are the use of shading devices, while the dependent variables observed are natural lighting levels and natural lighting factors. The results of this study are natural lighting systems in the form of design solutions that allow it to apply in the 3rd-floor library reading room at Budi Luhur University.

To address the limitations of traditional cadmium telluride (CdTe) photovoltaic (PV) windows in comprehensively considering overall building energy consumption, indoor lighting comfort, and outdoor visibility, this study proposes a three-domain division CdTe PV window design, which divides the window into three areas, each undertaking different functions. This study utilized the Energy Plus 9.3.0 software and Radiance 1.6.0 software for numerical simulation to explore the impact of different design parameters (such as coverage rate and arrangement mode of PV) of the three-domain division PV windows on building energy consumption and the proportion of indoor effective natural lighting (UDI300lx–2000lx) in single-story office buildings in Yan’an. Additionally, this study employed the entropy weight–TOPSIS method to conduct a comprehensive evaluation of 84 schemes. The results indicate that both the coverage rate and the arrangement mode of PV significantly influence building energy-saving and indoor lighting environment. The energy-saving rate initially increases and then decreases with higher PV coverage, while UDI300lx–2000lx generally exhibits an upward trend and slightly decreases later. The V3-V1 or H3-V1 arrangement mode demonstrates superior energy-saving performance, whereas the H3-V1 or V3-H1 arrangement mode provides better indoor lighting comfort. The evaluation weights for energy-saving rate and effective daylighting are 0.38 and 0.62, respectively. Based on the comprehensive evaluation, the optimal configuration is determined to be V1-90%-V2-10%-H3-90%, achieving an energy-saving rate of 11.1% and a UDI300lx–2000lx value of 56.95%.

Transparent roofs and walls offer a compelling solution for harnessing natural light. However, traditional glass roofs and walls face challenges such as glare, privacy concerns, and overheating issues. In this study, we present a polymer-based micro-photonic multi-functional metamaterial. The metamaterial diffuses 73% of incident sunlight, creating a more comfortable and private indoor environment. The visible spectral transmittance of the metamaterial (95%) surpasses that of traditional glass (91%). Furthermore, the metamaterial is estimated to enhance photosynthesis efficiency by ~9% compared to glass roofs. With a high emissivity (~0.98) close to that of a mid-infrared black body, the metamaterial is estimated to have a cooling capacity of ~97 W/m 2 at ambient temperature. The metamaterial was about 6 °C cooler than the ambient temperature in humid Karlsruhe. The metamaterial exhibits superhydrophobic performance with a contact angle of 152°, significantly higher than that of glass (26°), thus potentially having excellent self-cleaning properties. Transparent roofs offer a solution for harnessing natural light in sustainable buildings. Here, authors demonstrate a polymer-based metamaterial with micro-pyramid surface structures that diffuses sunlight while offering passive cooling and self-cleaning properties.

The cone photoreceptors in our eyes selectively transduce the natural light into spiking representations, which endows the brain with high energy-efficiency color vision. However, the cone-like device with color-selectivity and spike-encoding capability remains challenging. Here, we propose a metal oxide-based vertically integrated spiking cone photoreceptor array, which can directly transduce persistent lights into spike trains at a certain rate according to the input wavelengths. Such spiking cone photoreceptors have an ultralow power consumption of less than 400 picowatts per spike in visible light, which is very close to biological cones. In this work, lights with three wavelengths were exploited as pseudo-three-primary colors to form ‘colorful’ images for recognition tasks, and the device with the ability to discriminate mixed colors shows better accuracy. Our results would enable hardware spiking neural networks with biologically plausible visual perception and provide great potential for the development of dynamic vision sensors. Future intelligent vision systems need efficient capacitor-free spiking photoreceptor for color perception. Here, Wang et al. report a metal oxide-based vertically integrated spiking cone photoreceptor array which transduces light into spike trains with a power consumption of less than 400 picowatts.

Atomically defined assemblies of dye molecules (such as H and J aggregates) have been of interest for more than 80 years because of the emergence of collective phenomena in their optical spectra 1 – 3 , their coherent long-range energy transport, their conceptual similarity to natural light-harvesting complexes 4 , 5 , and their potential use as light sources and in photovoltaics. Another way of creating versatile and controlled aggregates that exhibit collective phenomena involves the organization of colloidal semiconductor nanocrystals into long-range-ordered superlattices 6 . Caesium lead halide perovskite nanocrystals 7 – 9 are promising building blocks for such superlattices, owing to the high oscillator strength of bright triplet excitons 10 , slow dephasing (coherence times of up to 80 picoseconds) and minimal inhomogeneous broadening of emission lines 11 , 12 . So far, only single-component superlattices with simple cubic packing have been devised from these nanocrystals 13 . Here we present perovskite-type (ABO 3 ) binary and ternary nanocrystal superlattices, created via the shape-directed co-assembly of steric-stabilized, highly luminescent cubic CsPbBr 3 nanocrystals (which occupy the B and/or O lattice sites), spherical Fe 3 O 4 or NaGdF 4 nanocrystals (A sites) and truncated-cuboid PbS nanocrystals (B sites). These ABO 3 superlattices, as well as the binary NaCl and AlB 2 superlattice structures that we demonstrate, exhibit a high degree of orientational ordering of the CsPbBr 3 nanocubes. They also exhibit superfluorescence—a collective emission that results in a burst of photons with ultrafast radiative decay (22 picoseconds) that could be tailored for use in ultrabright (quantum) light sources. Our work paves the way for further exploration of complex, ordered and functionally useful perovskite mesostructures. Through precise structural engineering, perovskite nanocrystals are co-assembled with other nanocrystal materials to form a range of binary and ternary perovskite-type superlattices that exhibit superfluorescence.