Solar Conversion Research Articles

Thermionic enhanced solar thermoradiative-photovoltaic conversion

Solar thermoradiative-photovoltaic (TR-PV) conversion is a promising power generation technique due to its flexible architecture. However, the TR-PV converter transforms energy from heat to electrons, then photons, and ultimately back to electrons, resulting in irreversible interconversion losses. This paper attempts to present a novel concept of solar thermionic intermediated thermoradiative-photovoltaic (TRTI-PV) conversion. Thermoradiative photons, as well as thermionic electrons are released and involved between the TR and PV ends, minimizing the irreversible loss of the electron-photon transition. A detailed thermodynamic model in which the nonradiative losses are taken into account is established for solar TRTI-PV conversion. The results demonstrate that the thermionic emission dominates the solar TRTI-PV conversion, with mutual restriction between the TR and PV components. The output power of the TRTI-PV converter rises to 35.54 W/cm2 at thermoradiative and photovoltaic bandgaps of 0.3 eV and 0.2 eV, respectively, despite the TR and PV component outputs being 1.67 W/cm2 and 3.63 W/cm2 respectively, substantially lower than those in TR-PVs. The TRTI-PV converter obtains a solar conversion efficiency of roughly 34.78% at a concentration ratio of 1000, which is 3.24 times that of a single TR-PV converter.

Petroleum Coke Embedded in Cigarette Butts: All Waste-Derived Solar Evaporator for Effective Water Evaporation.

Solar-driven interfacial evaporation is an eco-friendly solution for tackling the impending water scarcity the world is facing in our century. In this work, a solar-driven interfacial evaporator was prepared from cigarette butts loaded with petroleum coke powder (Filter-PetCoke), a by-product of the oil refinery processes, for the improvement of the absorption of the incident solar light. A comparison between a flat 2D and a 3D evaporator with a surface composed of orderly patterned protrusions of 2.1 cm was carried out to assess the influence of the evaporator configuration on the evaporation performance. The 3D evaporator (3D Filter-PetCoke) achieved by far the best performance (evaporation rate: 1.97 ± 0.08 kg m-2 h-1 and solar conversion efficiency: 93.2 ± 5.4%) among the prepared samples (3D Filter-PetCoke, 3D Filter, 2D Filter-PetCoke, and 2D Filter). In addition, this configuration seems to be adaptable for real and more massive operation because of the geometry of the evaporator. The high efficiency was ascribed to the good heat generation of the petroleum coke and the excellent heat management of the 3D structure of the evaporator. Moreover, this evaporator was resistant to multiple repeated usages without significant efficiency loss and capable of producing drinking water from seawater and Escherichia coli (E. coli)-contaminated water. The findings in this work indicate that this evaporator is pertinent to real situations to supply safe freshwater very efficiently from chemically/biologically contaminated water.

Engineering phase and vacancy with anchoring Fe nanoparticles for photothermal conversion in peroxymonosulfate activation toward efficient removal of carbamazepine

The peroxymonosulfate (PMS) based advanced oxidation processes had demonstrated great potential in water remediation, but the shortage of PMS active sites in the catalyst and the low conversion of active sites limited the wide application in practice. As a result, the design and synthesis of efficient and environmentally friendly catalysts for the activation of PMS had garnered significant attention. Thus, we enhanced electron transfer efficiency by introducing the metallic 1T phase into 2H phase molybdenum disulfide (THMS) and increased the active sites through the introduction of sulfur defects using the Joule heating strategy, resulting in the formation of defect-rich THMS (DTHMS). In addition, we anchored Fe nanoparticles (DTHMS@Fe) that could give rise to coupled photothermal and plasmon resonance effects under simulated sunlight irradiation to promote the activation of PMS and the dissociation of H2O, resulting in an augmented production of radicals. In the optimized DTHMS@Fe hybrid, an impressive degradation rate of Carbamazepine (CBZ) approached 99% within 15 min. The temperature of the DTHMS@Fe/PMS/light system was increased to 49 °C with irradiation for 10 min and the corresponding apparent rate reaches 0.35695 min−1 which was 8.9 and 5.7 times that of initial THMS (0.0398 min−1) and DTHMS (0.0622 min−1), respectively. Our work offered an innovative solution for constructing PMS co-activated systems by coupling solar photothermal conversion, enabling efficient degradation of organic pollutants while reducing costs and energy consumption.

Synthesis of dry water type molten marbles for fast photothermic conversion and heat storage by self-assembly method

A popular development direction of research in solar energy is the creation of new material with effective solar thermal conversion and outstanding energy storage capabilities. In this case, the “dry water model” is introduced in this study to create the spherical around 100 μm melting marble on hydrophobic surfaces by varying the ratio of eutectic phase change materials (PCM) and coating materials. After that, SEM (scanning electron microscopy) and STA (simultaneous thermal analyzer) were used to investigate the geometry and thermodynamic properties of the coating materials silica and graphene on marble. It is evident that the prepared molten marbles have a large specific surface area, anti-leakage stability, and the coating PCM capacity can reach >95 %. According to the results of contact angles tester and thermal imaging Camera, the black “dry water” that is created when graphene and silica are combined in a specific ratio and allowed to self-assemble on a hydrophobic substrate, has excellent mechanical stability and thermal storage capabilities. The xenon lamp was used to assess the photothermal conversion performance of various PCMs, and when compared to PCMs, the dry-water molten marble obtained 83 % photothermal conversion performance, 17 % higher thermal conductivity, and around three times the energy storage time.

Phase engineering of 1 T-MoS2 on BiVO4 photoanode with p–n Junctions: Establishing high speed charges transport channels for efficient photoelectrochemical water splitting

Photoelectrochemical (PEC) conversion of solar energy into chemical energy urgently requires attractive photoelectrodes to advance its practical application. Herein, we demonstrated a simple dopant electron strategy for phase control engineering and prepared a hybrid photoelectrode of 1 T-MoS2 nanosheets sensitized monoclinic BiVO4 (denoted as 1 T-MoS2@BiVO4) with p–n junction. The internal p–n heterojunction in the composite photoanode contributes to its superior charges transport. Further, the inserted 1 T-MoS2 layer at the BiVO4/traditional co-catalysts (OECs) (OECs: FeOOH and NiOOH) interface can profoundly improve the PEC water splitting and solar conversion efficiency of BiVO4-based photoanodes. The corresponding photocurrent density of FeOOH@1T-MoS2@BiVO4 photoelectrode (4.02 mA cm−2) is 3.5 times as high as that of the pure BiVO4 electrode (1.14 mA cm−2) at 1.23 V vs reversible hydrogen electrode (RHE), accompanied by a photoconversion efficiency of 1.28% at 0.68 vs RHE. Theoretical integrated with experimental studies reveal that the insertion of an 1 T-MoS2 layer between BiVO4 and OECs facilitates the establishment of high speed transport channels for holes and electrons. Subsequently, copper phthalocyanine (CuPc) as an unconventional hole-transporting organic material could maintain the photocurrent density of the composite photoanode for stability test over 8 h. Importantly, this study sheds light on the rational design of phase-control-based devices for solar-to-chemical energy conversion, and also implies a prospective nexus between BiVO4 and traditional or unconventional co-catalysts.

In situ growth of polydopamine modified ZIF-L arrays on air-laid paper as flexible evaporator for efficient solar desalination

The utilization of solar vapor generation for water purification plays a pivotal role in addressing the severe water scarcity crisis. However, it poses challenges due to inefficient light trapping and absorption limitations in solar thermal energy conversion. Here, we have strategically developed an array structured light trapping system with vertically grown, leaf-like zeolitic imidazolate framework (ZIF-L) nanosheets on flexible air-laid paper, accompanied by the catalytic effect of Co ions that result in oxidative polymerization of dopamine (DA) into pleated polydopamine (PDA) layers. This novel solution extends the propagation path of light in the trapping system through multiple scattering. Upon optimization, the P/ZIF-L@PDA-3 evaporator boasts an evaporation rate of 1.48 kg m−2 h−1 at 1 sun (1 kW m−2) irradiation and achieves an impressive solar vapor conversion efficiency of 94.5 %. In practical settings, the evaporation rate can reach 2.22 kg m−2 h−1 after 9 h with an average outdoor light intensity of 0.995 kW m−2. Our study presents an innovative approach to constructing a flexible evaporator with a light-trapping structure, providing immense potential for practical solar applications.

Regulation of d-Band Centers in Localized CdS Homojunctions through Facet Control for Improved Photocatalytic Water Splitting.

The accelerated kinetic behaviour of charge carrier transfer and its unhindered surface reaction dynamic process involving oxygenated-intermediate activation and conversion are urgently required in photocatalytic water (H2 O) overall splitting, which has not been nevertheless resolved yet. Herein, localized CdS homojunctions with optimal collocation of high and low index facets to regulate d-band center for chemically adsorbing and activating key intermediates (*-OH and *-O) have been achieved in H2 O overall splitting into hydrogen. Density functional theory, hall effect, and in situ diffuse reflectance infrared Fourier transform spectroscopy confirm that, electrons and holes are kinetically transferred to reductive high index facet (002) and oxidative low index facet (110) of the localized CdS homojunction induced by facet Fermi level difference to dehydrogenate *-OH and couple *-O for hydrogen and oxygen evolution, respectively, along with a solar conversion into hydrogen (STH) of 2.20 % by Air Mass 1.5 Global filter irradiation. These findings contribute to solving the kinetic bottleneck issues of photocatalytic H2 O splitting, which will further enhance STH.

Regulation of d‐Band Centers in Localized CdS Homojunctions through Facet Control for Improved Photocatalytic Water Splitting

AbstractThe accelerated kinetic behaviour of charge carrier transfer and its unhindered surface reaction dynamic process involving oxygenated‐intermediate activation and conversion are urgently required in photocatalytic water (H2O) overall splitting, which has not been nevertheless resolved yet. Herein, localized CdS homojunctions with optimal collocation of high and low index facets to regulate d‐band center for chemically adsorbing and activating key intermediates (*‐OH and *‐O) have been achieved in H2O overall splitting into hydrogen. Density functional theory, hall effect, and in situ diffuse reflectance infrared Fourier transform spectroscopy confirm that, electrons and holes are kinetically transferred to reductive high index facet (002) and oxidative low index facet (110) of the localized CdS homojunction induced by facet Fermi level difference to dehydrogenate *‐OH and couple *‐O for hydrogen and oxygen evolution, respectively, along with a solar conversion into hydrogen (STH) of 2.20 % by Air Mass 1.5 Global filter irradiation. These findings contribute to solving the kinetic bottleneck issues of photocatalytic H2O splitting, which will further enhance STH.

Comparison of Control Method System by Using Perturbation and Observation Algorithms and Fuzzy Logic for the Maximum Power Point Control in Photovoltaic Systems

Currently, photovoltaic energy conversion has developed tremendously in the global energy industry. The enormous capacity of solar power plants generates electricity all over the world. Hundreds of gigawatts of electrical energy are supplied to the networks of various countries around the globe. In addition, up to hundreds of gigawatts of installed capacity of solar power plants are commissioned every year in all countries of the world. And this has been the trend for the past few decades. The main problem of solar photovoltaic conversion is the instability of the solar radiation flux associated with the climatic conditions in the regions where photovoltaic plants are operated. This problem can be solved by using highly efficient methods to control the generation of solar power plants, in particular, such as the use of information control systems for a particular PV system to increase the final generation of electrical energy supplied to the consumer. The photovoltaic (PV) conversion of solar radiation flux is an important renewable energy source. Due to the varying intensity of the sun, the electricity generated by PV directly from the radiation flux is not constant. The photovoltaic system currently uses maximum power point (PMP) tracking in perturbation and observation (P&O) mode to increase the final output power of the photovoltaic panels. A step-down DC-DC converter allows PMP to change the PV operating voltage and determine the maximum power output of the PV panel. This study proposes a fuzzy logic implementation. The magnitude of the perturbed voltage is determined by the change in power dq and the change in power relative to the change in voltage dq/dv is fuzzy. The performance of fuzzy logic is investigated in this work in order to optimize MPM. Fuzzy logic can simplify maximum power tracking and reduce voltage instability. According to the simulation results, the MPM method based on fuzzy computation performs better than the traditional P&O method. By using the proposed methods, we can significantly improve electric power generation and increase the efficiency of photovoltaic conversion.

Topological Analysis and Solar Grid-Tied Integration of Level Building Network Based Extendable High Power Multilevel Converter

This paper presents a new solar multilevel converter (SMLC) with closed-loop control to integrate solar PV arrays with medium voltage 3.3 kV grid. This multilevel converter produces higher number of levels in the output voltage with less usage of semiconductor switches. This solar converter utilizes only ten switches and three PV sources with equal voltage to have seven levels in the output voltage. The main motive is to have minimum switches, which reduces the count of driver circuits for a power converter. Moreover, a reduced switch converter requires less space in terms of installing the power and auxiliary components. This solar power converter comprises a solar photovoltaic (SPV) array fed level building network (LBN) nested within the six switches connected in a rectangular arrangement. The converter has two PV sources at its upper and lower ends. This solar converter is also ideal for asymmetric configurations. Moreover, the increase in solar input power is possible with more count of the LBNs. The converter switching states and operating path demonstrate the working operation of the new solar PV system. A comparison of the proposed solar converter is made with existing multilevel topologies. The system is modeled and executed in closed-loop control to showcase its effectiveness for solar power conversion. The solar converter transfers the power in varying solar conditions successfully.

Research on route planning for solar UAV based on the intelligent optimization algorithm.

The solar unmanned aerial vehicle (UAV) route planning needs to comprehensively consider the conversion efficiency of solar cells under the influence of solar ground reflection radiation and sky scattering radiation. On the one hand, it is necessary to consider the cost of radar threat, mileage energy consumption, mountain impact and other costs. On the other hand, it is also necessary to consider the influence of high threat, mountain shadow occlusion cost, and cloud shading cost on solar photovoltaic conversion efficiency. The above problem was solved through using the ant colony intelligent optimization algorithm. By constructing ant colony paths rationally, models of mountain impact cost, high threat, mountain shadow shelter cost, and cloud shading cost were established. The constraints such as the maximum action distance, solar irradiation angle and effective action distance of various costs were introduced into the cost model and exploration factor calculation, and the comprehensive optimization problem of solar UAV route was solved. Finally, the simulation results show that the algorithm path structure is reasonable; the target node can be found independently; the convergence speed can meet the requirements of route planning; the generated route cost is small; the algorithm is reasonable and effective.

Enhanced dry reforming of CO2 and CH4 on photothermal catalyst Ru/SrTiO3

CH4 and CO2, which are greenhouse gases, can be converted into valuable syngas through the solar-powered photothermal dry reforming of methane (DRM); this process also facilitates the collection and storage of solar energy. However, conventional photothermal catalysts insufficient catalytic activity for light enhancement at high temperatures. Herein, we report a photothermal catalyst Ru/SrTiO3. The yields of CO and H2 were 1.4–1.5 times those obtained using the thermocatalytic process at 600 ℃ and under 300-W xenon lamp irradiation. Based on in situ–irradiated X-ray photoelectron spectroscopy and density functional theory calculations, light can induce electron transfer from SrTiO3 to Ru in Ru/SrTiO3 catalysts and participate in CH4 dehydrogenation and H2 generation, lowering its reaction energy barrier. Moreover, photogenerated electrons can suppress the occurrence of inverse water–gas reaction. This study clarifies the mechanism of the photothermal DRM, providing a useful guide for the future solar photothermal conversion of greenhouse gases.

Design and Analysis of Comprehensive Solar Utilization System Based on Photovoltaic Concentration and Spectral Splitting

In order to address the issue of a solar utilization system with low efficiency, this paper designs a new solar conversion system based on photovoltaic concentration and spectral splitting. The system concentrates sunlight through a Fresnel lens and uses a hollow concave cavity to evenly distribute the incident energy flow. The spectral splitting medium separates the useful irradiance for the PV cell from those wavelengths that are more suited to heat generation. By considering the available wavelength of photovoltaic cells, the GaAs cell and a ZnO nanofluid were selected for this paper. It was found that installing the hollow concave cavity improved the spot uniformity of the PV cell surface by 17%. The output efficiency of the system under various circumstances was analyzed. The results show that at a concentration ratio of 50 and a light intensity of 1000 W/m2, photoelectric conversion efficiency increased by 0.81%. When compared to direct concentration, the photoelectric conversion efficiency increased by at least 7%. Meanwhile, the comprehensive electrical efficiency was 36.7%, which is higher than that of the normal concentration PV and comprehensive thermal system.

Optimising standard solar cell designs for maximum efficiency using genetic algorithms

ABSTRACT Solar energy is an alternative to conventional fossil fuels, and maximising the energy collected through solar cell design improvements is worthwhile. Genetic algorithms (GAs) have been historically useful in pursuing design improvements in solar cell architecture and manufacturing, particularly in combination with cell modelling software. This study demonstrates solar cell structural optimisation using PC3D software in combination with a genetic algorithm (GA) to maximise solar cell power conversion efficiency. PC3D is an Excel-based tool for modelling solar cells. The cell models examined here are: Passivated-Emitter Rear Contact (PERC), Interdigitated Back Contact (IBC), Aluminium-Back Surface Field (Al-BSF), and Passivated-Emitter Rear Locally Diffused (PERL). These are all silicon PV cells with varying structural features that significantly alter the performance of each cell. Absolute efficiency improvements of 2% for PERC, 1.6% for Al-BSF, 0.9% for IBC, and 0.5% for PERL cells are achieved. The main parameters impacting cell efficiency in this model are cell thickness and minority charge carrier lifetime, which feature a necessary trade-off between the higher absorption resulting from a thicker cell and the increased likelihood of charge collection arising from longer carrier lifetimes. These parameters are managed through other related values such as cell doping.

Strain-Induced SiP–PtS2 Heterostructure with Fast Carrier Transport for Boosted Photocatalytic Hydrogen Conversion

Earth-abundant silicon-, phosphorus-, and sulfur-related compounds are crucial for optoelectronic application. Specifically, experimentally proven monolayer SiP has attracted a great deal of attention in above listed field owing to its unique properties but is plagued with challenges such as photocorrosion and poor charge separation. Moreover, theoretical understanding on the relationship of the interface and photocatalytic activity in SiP-based chemicals is not well understood. In this work, hybrid functional first-principles calculations were used to explore the photocatalytic hydrogen evolution activity of SiP–PtS2 heterostructure. Further examination of phonon, ab initio molecular dynamics (AIMD), and elastic property simulations confirms its dynamical stability. Its computed band gap of 1.59 eV is suitable for maximizing solar energy conversion efficiency, with noticeable strong absorption coefficients of 105 cm–1 order across visible–ultraviolet domains, asymmetric decent carrier mobility (∼103 cm2 V–1 s–1), and low exciton binding energy (0.56 eV). Differences in charge density and Bader and Mulliken population analyses reveal that charge flows from the SiP to the PtS2 layers, performing the dual functions of segregating photoinduced charge carriers and increasing their lifetimes. The relative band alignment of the monolayers promotes a spatial separation of the charges. An important feature of this heterostructure is that the band edges cross the water redox potential at pH of 0 upon −2% of compressive biaxial straining, with ΔG for hydrogen evolution reaction (HER) barrier lower than −0.2 eV. The quadratic relationship between biaxial strain and atomic energy indicates that both the system and strains are elastic. Redox thermodynamic analysis predicts facile hydrogen production on the heterostructure. In particular, the calculated maximum solar power conversion efficiency (PCE) and solar-to-hydrogen (STH) efficiency can reach 22.9 and 23.8%, respectively.

Engineering Exciton Dynamics with Synthetic DNA Scaffolds.

ConspectusExcitons are the molecular-scale currency of electronic energy. Control over excitons enables energy to be directed and harnessed for light harvesting, electronics, and sensing. Excitonic circuits achieve such control by arranging electronically active molecules to prescribe desired spatiotemporal dynamics. Photosynthetic solar energy conversion is a canonical example of the power of excitonic circuits, where chromophores are positioned in a protein scaffold to perform efficient light capture, energy transport, and charge separation. Synthetic systems that aim to emulate this functionality include self-assembled aggregates, molecular crystals, and chromophore-modified proteins. While the potential of this approach is clear, these systems lack the structural precision to control excitons or even test the limits of their power. In recent years, DNA origami has emerged as a designer material that exploits biological building blocks to construct nanoscale architectures. The structural precision afforded by DNA origami has enabled the pursuit of naturally inspired organizational principles in a highly precise and scalable manner. In this Account, we describe recent developments in DNA-based platforms that spatially organize chromophores to construct tunable excitonic systems. The high fidelity of DNA base pairing enables the formation of programmable nanoscale architectures, and sequence-specific placement allows for the precise positioning of chromophores within the DNA structure. The integration of a wide range of chromophores across the visible spectrum introduces spectral tunability. These excitonic DNA-chromophore assemblies not only serve as model systems for light harvesting, solar conversion, and sensing but also lay the groundwork for the integration of coupled chromophores into larger-scale nucleic acid architectures.We have used this approach to generate DNA-chromophore assemblies of strongly coupled delocalized excited states through both sequence-specific self-assembly and the covalent attachment of chromophores. These strategies have been leveraged to independently control excitonic coupling and system-bath interaction, which together control energy transfer. We then extended this framework to identify how scaffold configurations can steer the formation of symmetry-breaking charge transfer states, paving the way toward the design of dual light-harvesting and charge separation DNA machinery. In an orthogonal application, we used the programmability of DNA chromophore assemblies to change the optical emission properties of strongly coupled dimers, generating a series of fluorophore-modified constructs with separable emission properties for fluorescence assays. Upcoming advances in the chemical modification of nucleotides, design of large-scale DNA origami, and predictive computational methods will aid in constructing excitonic assemblies for optical and computing applications. Collectively, the development of DNA-chromophore assemblies as a platform for excitonic circuitry offers a pathway to identifying and applying design principles for light harvesting and molecular electronics.

Effect of morphological evolution and aggregation of plasmonic core-shell nanostructures on solar thermal conversion.

Achieving high solar energy absorption based on nanofluids (NFs) needs further study in solar photothermal conversion technology. In this work, we performed COMSOL simulations to investigate the solar energy absorption using a core-shell nanostructure composed of the Au core and shell with different materials. The influence of the radius of the Au core, the materials of the shell, and the shell thickness on the solar absorption efficiency factor (SAEF) are systematically studied. The results show that the SAEF of the Au@Li nanoparticle with ratio of 0.5 has the highest SAEF of 1.4779, increasing 1.99 times compared to that of the bare Au nanoparticle of 0.74326 with the same radius. Moreover, the optical properties, electric field distribution, and SAEF of the Au@Li dimer are further evaluated to demonstrate the aggregation effects on SAEF. We find that the SAEF of the Au@Li dimer reaches the maximum of 4.34 with a distance around 1nm, where the LSPR coupling effect in the nanogap is sharply enhanced 700 times irradiated by light with wavelength of 760nm. Finally, the direct absorber solar collector performance demonstrates that Au@Li dimer NFs can collect 93% of solar energy compared to 54% for Au@Li NFs and 51% for Au NFs. This work provides the possibility to achieve more efficient solar thermal conversion, and may have potential applications in efficient solar energy harvesting and utilization.

Fabrication of structure-improved, sintering-resistant Li4SiO4 materials for stabilized thermochemical energy storage in concentrated solar power plants

Thermochemical energy storage has been considered as a promising technology for the future high-temperature solar thermal conversion and utilization in concentrated solar power plants. In this work, Li4SiO4/CO2 thermochemical energy storage system was designed based on the reversible reaction Li4SiO4 + CO2↔Li2SiO3 + Li2CO3. The proposed Li4SiO4-based system, which possesses a heat releasing temperature of ∼700 °C, fills in the gaps of medium temperature TCES materials. Furthermore, structure-improved, sintering-resistant Li4SiO4 materials with stabilized performance were fabricated by using organic lithium precursor and cerium addition, and corresponding enhancement mechanisms were systematically studied. It is concluded that the utilization of lithium salicylate could effectively improve the surface morphology as well as the specific surface area of Li4SiO4 particles. And the Ce addition could enhance the cyclic stability of Li4SiO4 by forming anti-sintering CeO2 fine particles inside. As a result, the obtained L-S-Ce2.5 exhibits an average capacity of 671.3 kJ/kg with the capacity decay as low as 13 kJ/kg per cycle, which is of great significance for the practical long-term heat storage/releasing applications at medium temperature.

Plants transpiration-inspired antibacterial evaporator with multiscale structure and low vaporization enthalpy for solar steam generation

Solar-driven vapor generation by localized solar heating of a photothermal material is an environmentally friendly approach for seawater desalination and wastewater purification. In this work we designed a novel bionic evaporator, inspired by plant transpiration in nature, to realize highly efficient solar vapor generation. The plant transpiration inspired three-dimensional structure has a hydrophilic cellulose skeleton with high porosity and low thermal conductivity, and decorated with photothermal polypyrrole (PPy) that self-organize as nano branches and leaves exhibiting excellent photothermal conversion capacity. The cellulose skeleton has microchannels that facilitates water transport and reduces the water evaporation enthalpy. PPy nano branches and leaves can not only efficiently absorb and convert sunlight, but the thermal gradient distribution in this microstructure induces Marangoni convection which guarantees efficient water transportation in evaporative regions. Moreover, the coupling of external wind fields further enhances the rate of vapor escape. The as-fabricated vapor generator based on the bionic structure achieved an impressive high evaporation rate of 2.05 kg m−2 h−1 under one sun (1 kW m−2) irradiation, with the solar thermal conversion efficiency up to 97.7%. A significantly higher water vapor generation rate of 2.9 kg m−2 h−1 is obtained under one sun irradiation at a wind speed of 2 m s−1. In addition, the evaporator has excellent photothermal antibacterial activity against both E. coli and S. aureus. This bionic evaporator offers a potential low-cost and highly efficient water purification technology that could help mitigate the global water crisis.

Recent Progress in Perovskite Tandem Solar Cells.

Tandem solar cells are widely considered the industry's next step in photovoltaics because of their excellent power conversion efficiency. Since halide perovskite absorber material was developed, it has been feasible to develop tandem solar cells that are more efficient. The European Solar Test Installation has verified a 32.5% efficiency for perovskite/silicon tandem solar cells. There has been an increase in the perovskite/Si tandem devices' power conversion efficiency, but it is still not as high as it might be. Their instability and difficulties in large-area realization are significant challenges in commercialization. In the first part of this overview, we set the stage by discussing the background of tandem solar cells and their development over time. Subsequently, a concise summary of recent advancements in perovskite tandem solar cells utilizing various device topologies is presented. In addition, we explore the many possible configurations of tandem module technology: the present work addresses the characteristics and efficacy of 2T monolithic and mechanically stacked four-terminal devices. Next, we explore ways to boost perovskite tandem solar cells' power conversion efficiencies. Recent advancements in the efficiency of tandem cells are described, along with the limitations that are still restricting their efficiency. Stability is also a significant hurdle in commercializing such devices, so we proposed eliminating ion migration as a cornerstone strategy for solving intrinsic instability problems.