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The monolithic perovskite/silicon tandem solar cells (TSCs) have a theoretical efficiency of more than 42%, now the record efficiency has reached 33.9%. In this review, the structure of perovskite/silicon TSCs, the antireflection layer, front transparent electrode, wide-bandgap perovskite solar cells (WB-PSCs), carrier transport layers, and intermediate tunneling junction are mainly presented that influence the efficiency of TSCs. Current-matching, optical losses are analyzed to improve the performance of TSCs. In the end, to meet the commercial application, the stability, manufacturing scalability and cost-effectiveness of TSCs are analyzed. In brief, a general overview is provided on the recent advances in perovskite/silicon TSCs from materials and devices development and some personal perspectives on the future commercial application of TSCs. [Display omitted] [ABSTRACT FROM AUTHOR]

In 2011 Historic Royal Palaces began to investigate protective measures for historic tapestries on open display at Hampton Court Palace. The environmental exposure conditions for each tapestry were analysed and mapped to evaluate risk. An innovative method to reduce illuminance and direct sunlight on the historic tapestries using 'smart' technologies was developed. The design, testing and implementation of the installation of Smart Tint liquid crystal films whose optical appearance can be switched electrically from opaque to transparent, are presented. Substantial reduction (>90%) in direct light transmission could be achieved when the film is opaque. It also provides additional protection from ultraviolet (99%) and infrared radiation (98%). An entirely reversible and customised installation method had to be devised using pressure-fixed lightweight aluminium frames. An automated controller was also installed to change the individual windows from clear to opaque during different times of the day depending on their orientation and the time of the year while a dedicated wireless mesh network system enabled communication between each window and the controller. The impact of this installation is described. The use of 'smart' technologies offered dynamic light protection for collections on open display while maintaining the presentation of the historic room. The benefits of adopting this innovative technology include its flexible and unobtrusive installation. [ABSTRACT FROM AUTHOR]

Abstract Perovskite/silicon tandem solar cells (TSCs) have the potential to achieve power conversion efficiency exceeding 30%. To be compatible with high-efficiency solution-deposited perovskite top cell, a planar front surface for silicon bottom cell is generally required. However, flat front surfaces result in large light reflection losses and thus reduce the performance of tandem device. To boost light absorption, we design light management antireflective foils made from polydimethylsiloxane (PDMS) polymer carrying random-pyramidal textures with three different pyramid size ranges (1–3 µm, 3–8 µm, 8–15 µm). The optical properties, together with the reflection behavior applied to perovskite/silicon tandem solar cells have been systematically studied. One of the PDMS layer exhibited a relatively strong light-scattering property with a high average haze ratio originated from synergistic effect of the appropriate pyramid size and the uneven random pyramid distribution. Consequently, the short-circuit current density of the tandem device was improved by 1.72 mA/cm2 and thus its efficiency increased from 19.38% to 21.93%, after laminating the PDMS-based antireflection coating (ARC) onto the front surface of tandem device. Furthermore, this work provides a facile and cost-effective way to introduce light-management foils and indicates a broad strategy to enhance the performance of solar cells with planar front surface. Graphical abstract fx1 Highlights • Different inverted pyramidally-textured PDMS foils with random distribution were studied. • The integrated currents of the two sub-cells were improved with PDMS. • With P2-PDMS, the J SC of the TSC was increased by 1.72 mA/cm2. • The PDMS foil has good performance stability. [ABSTRACT FROM AUTHOR]

Coordinated light management as one of the most essential strategies to further improve the power conversion efficiencies (PCEs) of perovskite solar cells (PSCs), which can achieve stronger light trapping, coupling and absorption through submicron nanostructured morphologies relative to planar structure. However, the interfacial preparation of textured-structures has been facing great challenges, which has severely limited the research progress in the field of optical structures of PSCs. Here, in situ growth of inorganic Cs-based perovskite recrystallized-arrays (CPRA) on the perovskite surface was realized by pseudo-halide anion solvent engineering. This preparation procedure of the CPRA is very facile and cost-effective. The induced recrystallization involved in the CPRA synthesis process is non-invasive to the underlying perovskite. It is experimentally and theoretically shown that highly recrystallized-arrays can provide excellent optoelectronic performance. The open circuit voltage (V OC) of the champion PSC modified by this wide-bandgap CPRA can exceed 1.20 V, and the PCE can reach 23.23%. Moreover, this scheme has the function of tuning the bandgap, which can increase the V OC of device up to 1.23 V (PCE 22.12%). The long-term stability of the CPRA-modified PSCs is also prominent based on the inherent lotus hydrophobic properties of the bionic arrays. [Display omitted] • In situ growth scheme of optical perovskite recrystallized-arrays is proposed. • The pseudo-halide anion solution can promote the consistency of lattice orientation. • The bulk heterojunction effect achieves the optimal carrier transport. • Photovoltaic performance and humidity stability are enhanced. [ABSTRACT FROM AUTHOR]

Enhancing the low-energy sunlight harvesting is of great importance for improving the efficiency of organic-inorganic halide perovskite solar cells (PSCs) but still remains a big challenge. Herein, we propose an improved light harvesting and management strategy by using rationally-designed Au@Ag core-shell nanocuboids as plasmonic inclusions, aiming at achieving panchromatic thin PSCs. Compared to conventional metal nanostructures with a single narrow plasmon resonance band, the Au@Ag nanocuboids exhibit multiple broader and stronger plasmon resonances that can be tuned by adjusting structural dimensions to spectrally match the absorption band of the perovskite, particularly in its weak absorption region. By carefully tailoring the location of the Au@Ag nanocuboids in the electrodes, both plasmonic near-field enhancement and increased light-scattering effects can be fully exploited to boost up the performance of the PSCs. As a result, the hybrid devices demonstrate high photon-to-electron conversion efficiency (IPCE) over the entire visible range, with a remarkable IPCE enhancement (ΔIPCE/IPCE) of 20–60% in the range of 550–750 nm, compared with pristine devices. This also leads to an average power conversion efficiency (PCE) of 17.83% for the optimized Au@Ag incorporated cells, with a champion PCE of 18.31% recorded for the best plasmonic PSC, corresponding to a PCE enhancement of 20.8%. [ABSTRACT FROM AUTHOR]

In recent years, thin-film silicon solar cells on glass prepared by liquid-phase crystallization have made progress towards high efficiency solar cells. Current record cells reach wafer-equivalent material quality and morphology using thin-film technologies. However, short-circuit current densities and hence, efficiencies, are still limited. The reflection at the interface between glass superstrate and silicon absorber layer has been identified as one major loss mechanism. These optical losses can be reduced by nanostructuring of the interface. It is important, however, that this nanostructured interface does not lead to a deterioration of silicon material quality simultaneously. Recently, we introduced SMooth Anti-Reflective Three-dimensional (SMART) textures, which consist of temperature-stable SiO x sol-gel nanostructures and a smoothing layer of spin-coated TiO x . These SMART textures on glass superstrates exhibit a smooth interface morphology and hence allow growing high-quality silicon absorber layers by liquid phase crystallization. Here, we investigate the optical properties of the SMART textures with and without an additional SiN x layer in experiment and by 1-dimensional optical simulations. It is shown that both, the SMART textures with and without additional SiN x layer, can outperform the optimized planar interlayer system of current record solar cell devices. Very low mean reflectance values of 11.2% are found in the wavelength regime from 400 nm to 600 nm for an optimized texture consisting of a 50 nm thick SMART texture with additional 15 nm SiN x layer. [ABSTRACT FROM AUTHOR]

A resonant-cavity-enhanced solar cell with a 25 nm thick amorphous germanium nanoabsorber is demonstrated. The device is specifically designed for use as bottom cell in multijunction devices. In this case, instead of relying on broadband absorption, only red light needs to be absorbed in the bottom cell. This allows exploiting the narrow resonance patterns of long Fabry-Pérot cavities to achieve efficient absorption inside the nanoabsorber. It is shown that this approach can only be integrated into multijunction devices when suppressing inter-subcell coherence. To achieve this, the intermediate reflector of the tandem device is textured using electrochemically grown zinc oxide nanorods. [ABSTRACT FROM AUTHOR]

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In the thin-film photovoltaic industry, to achieve a high light scattering in one or more of the cell interfaces is one of the strategies that allow an enhancement of light absorption inside the cell and, therefore, a better device behavior and efficiency. Although chemical etching is the standard method to texture surfaces for that scattering improvement, laser light has shown as a new way for texturizing different materials, maintaining a good control of the final topography with a unique, clean, and quite precise process. In this work AZO films with different texture parameters are fabricated. The typical parameters used to characterize them, as the root mean square roughness or the haze factor, are discussed and, for deeper understanding of the scattering mechanisms, the light behavior in the films is simulated using a finite element method code. This method gives information about the light intensity in each point of the system, allowing the precise characterization of the scattering behavior near the film surface, and it can be used as well to calculate a simulated haze factor that can be compared with experimental measurements. A discussion of the validation of the numerical code, based in a comprehensive comparison with experimental data is included. [ABSTRACT FROM AUTHOR]

Summary Since light management is crucial for the performance of optoelectronic devices, extensive efforts, such as texturing semiconductor layers and implementing plasmonic metal nanostructures or transparent dielectric structures, have been made to enhance the optical properties of the devices. It is advantageous that the implementation of transparent dielectric structures in the devices enables us to improve optical properties with minimized parasitic absorption loss and little deterioration of electrical property in the active layer. By properly designing geometry of structure and appropriately selecting dielectric material property, we can effectively control the efficiency of light transmission, extraction, scattering, or reflection. Hence, efficient light management using lossless dielectric structures gives great potential for improving the performance of the optoelectronic devices such as photovoltaic cells, photodetectors, light emitting diodes, and displays. In this review article, we will summarize the latest research progress on light management strategies for high-performance optoelectronic devices using transparent dielectric micro and nanostructures. [ABSTRACT FROM AUTHOR]

Radial pn junction Si micro/nano-wire arrays exhibit unique optical and electrical characteristics for building photovoltaic devices with high performance-to-cost ratios over traditional planar junction bulk Si structures. Through optimizing the structural parameters, such as wire diameter and array periodicity, antireflection even superior to the optimized antireflective coatings can be realized. In the meantime, excellent light confinement is easily achievable for Si micro/nano-wire arrays using much less materials compared to their bulk Si counterparts. From the electrical aspect, the radial pn junction configuration formed around the wires significantly reduces the minority carrier collection length along the radial direction, providing outstanding tolerance to material qualities. Owing to these charming properties, radial junction Si micro/nano-wire array-based solar cells have been attracting extensive attention. The power conversion efficiency has also made huge progress from <1% to the present >12% in less than 10 years. With cell performance improvement, the number of research papers regarding theoretical understanding and optimization of the optical and electrical processes, experimental reports of the related solar cells has also surged, also including review papers. Accordingly, in this paper we are focusing on the recent progress, following a brief but systematic introduction to the related topic. Then the issues needing to be addressed for further improving the optical and electrical structures and cell performance are summarized. Following that, several other advanced solar cells employing Si micro/nano-wire arrays as a platform are introduced. [ABSTRACT FROM AUTHOR]

Abstract: Line- and hexagonal-like periodic textures were fabricated on aluminium zinc oxide (AZO) using direct laser interference patterning method. It was found that hexagonally patterned surfaces show a higher performance in both transparency and diffraction properties compared to line-like textured and non-patterned substrates. Furthermore, the electrical resistance of the processed AZO coated substrates remained below the tolerance values for transparent conducting electrodes. [Copyright &y& Elsevier]

Plant response to blue, red, gray or black shade cloth was evaluated with willow oak (Quercus phellos L.), Nuttall oak (Quercus nuttallii Palmer, Nuttall) and Summer Red maple (Acer rubrum L. 'Summer Red') liners. Light transmitted through the colored shade cloth had no influence on germination of willow oak acorns or height and caliper growth following germination. Tree height, trunk diameter, number of internodes, shoot and root dry weight were generally greater with the species tested when exposed to red or gray shade cloth, but were often similar to plants exposed to blue or black shade. Height increase of willow oak with red shade was similar to plants exposed to blue or gray; however, the average number of internodes was similar with oaks exposed to blue shade and 16% less with oaks exposed to gray shade. Summer Red maples exposed to black, blue or red shade cloth were similar in height, though plants with blue shade had 23% less dry weight. Nuttall oaks exposed to gray shade had the greatest height increase while the plants exposed to red shade had the largest trunk diameter. The growth parameters measured showed some increases with exposure to colored shade, but the morphology of the species tested was not significantly altered to recommend the use of colored shade during production. [ABSTRACT FROM AUTHOR]

Abstract: In thin-film silicon solar cells (TFSC) efficient light management is essential in order to increase energy conversion efficiency. The application of nano-scale periodic gratings (PG) is a promising method to enhance absorption in the absorber layers of TFSC since they can efficiently scatter the incident light. Carefully designed gratings give a possibility to increase the photocurrent over a wavelength range where silicon exhibits a weak absorption. Maxwell''s equations solver was employed to carry out optical simulations of TFSC with PG. Atomic force microscopy (AFM) measurements demonstrate that film deposition smoothens the morphology of PG. In the simulations we used the results of AFM measurements to define the morphology of interfaces between the layers of TFSC. An optimum smoothing of interface roughness was determined that resulted in maximum absorption in thin-film silicon solar cells. [Copyright &y& Elsevier]

Abstract The ever-increasing demand for food, valuable bio-based compounds and energy has triggered the development of novel and sustainable resources. Microalgae are a promising source of sustainable high-value products. The need for light (suitable intensity and wavelength) and temperature control in microalgal cultures remains the most significant challenge limiting their photosynthetic efficiency and productivity. Appropriate light management has the potential to concurrently maximize photosynthetic productivity and control the temperature of microalgal photobioreactors resulting in a reduction in overall production costs. Here, we review innovations to improve light conversion efficiency and temperature control, such as spectral filtration, plasmonic waveguides, spectral shifting, wireless light emitters and insulated glazing, which typically increase the photosynthetic productivity, while avoiding overheating in photobioreactors. Infrared filtering reduces culture overheating in closed photobioreactors. Spectral shifting, plasmonic waveguiding, switchable glass and insulated glazing technologies can improve light quality received by algal cells. Improving light efficiency and distribution in the algal cultures can significantly enhance biomass productivity when used in open or closed cultivation systems. Based on this background, we illuminate the effectiveness of embedding the above-mentioned technologies into a novel insulated-glazed photovoltaic flat panel photobioreactor for simultaneously increasing the biomass and generating electricity, thus, eliminating the need for cooling systems. This approach opens the way for the development of cost-effective, low-carbon-footprint grid-independent integrated algae-based biorefineries with multi-product yields. Highlights • Significant losses in light energy efficiency affect algal productivity. • Light management enhances photosynthetic efficiency and maximizes productivity. • Tuning light spectra incident on cultures enhances production of specific bioproduct. • Large-scale application is a function of economic and implementation feasibility. • Integrating several management strategies creates energy-efficient culture systems. [ABSTRACT FROM AUTHOR]