Light-harvesting Materials Research Articles

T-Shaped-N-Doped Polycyclic Aromatic Hydrocarbons: A New Concept of Dopant-Free Organic Hole-Transporting Materials for Perovskite Solar Cells.

Although metal halide perovskites are positioned as the most powerful light-harvesting materials for sustainable energy conversion, there is a need for a thorough understanding of molecular design principles that would guide better engineering of organic hole-transporting materials, which are vital for boosting the performance and stability of perovskite solar cells. To address this formidable challenge, here, we developed a new design strategy based on the curved N-doped polycyclic aromatic hydrocarbon merged with T-shaped phenazines being decorated with (phenyl)-di-p-methoxyphenylamine (OMeTAD)─N-PAH23/24 and -3,6-ditertbutyl carbazole (TBCz)─N-PAH25/26. As N-PAH23/24 exhibited satisfying thermal stability, the comparative studies performed with various experimental and simulation methods revealed a pronounced correlation between the depth of the central cyclazine core and the form of the T-shape units. This proved to be a crucial factor in controlling their π-π intermolecular interaction as well as self-assembly behavior with the perovskite layer, leading to enhanced humidity resistance, operational stability, and a maximum power conversion efficiency of 20.39% denoted for N-PAH23, which is superior to the benchmarked device with doped spiro-OMeTAD (19.23%). These studies not only resulted in optimized stability and device performance but also opened a conceptually new chemical space in the photovoltaic technology.

SCAPS numerical modeling of CBTS/WO3 thin film solar cell

The quaternary compound Cu2BaSnS4 (CBTS) has emerged as a suitable and attractive light-harvesting material due to its promising optoelectronic features as well as nontoxic and low-cost constituent elements. Yet efficiency of CBTS-based solar cells did not reach the Shockley-Queisser limit. Here, what we believe to be a novel structure ITO/WO3/CBTS heterojunction solar cell is designed and modeled using a solar cell capacitance simulator in one-dimension (SCAPS-1D). In this work, a what we also believe to be a novel WO3 as a buffer layer is proposed for the first time for the efficiency enhancement of CBTS thin film solar cells. Numerical investigation of the performance of CBTS-based solar cells without and with cuprous oxide (Cu2O) back surface field (BSF) is explored. The impact of thickness, doping density, bulk, and interface defect density of an absorber, buffer and window layer, working temperature, shunt and series resistance, back contact work function, and back surface recombination velocity were analyzed and optimized without and with the BSF layer. In this work, the optimized solar cell achieved an efficiency of 18.8%, fill factor (FF) of 83.79%, short-circuit current density (JSC) of 15.99 mA/cm2, and open circuit voltage (VOC) of 1.4 V without Cu2O BSF layer at optimal CBTS absorber and WO3 buffer layer thickness of 2 µm and 0.04 µm respectively. Furthermore, the efficiency boosted to 21.12% with VOC of 1.43 V, JSC of 16.8 mA/cm2 and FF of 87.77% by inserting 0.1 µm Cu2O BSF layer. Therefore, these results will facilitate the fabrication of an efficient and low-cost CBTS-based solar cell with promising WO3 and Cu2O as buffer and BSF layer, respectively.

Surface Reaction Induced Compressive Strain for Stable Inorganic Perovskite Solar Cells.

Cesium-based inorganic perovskites have emerged as promising light-harvesting materials for perovskite solar cells (PSCs) due to their promising thermal- and photo-stability. However, obstacles to commercialization remain regarding their phase instability. In this work, we report a facile and effective strategy to regulate the surface compressive strain via in situ surface reaction to stabilize CsPbI3 perovskite. The use of a chelating ligand with a molecular configuration closely matching the integer multiples of the unit cell lattice parameters of CsPbI3 induces compressive strain at the surface of CsPbI3. The chemical bonding and strain modulation synergistically not only passivate film defects, but also inhibit perovskite phase degradation, thus significantly improving the intrinsic stability of inorganic perovskite. Consequently, enhanced power conversion efficiency (PCE) of 21.0 % and 18.6 % were respectively achieved in 0.16-cm2 lab-scale devices and 25.3-cm2 solar modules. Further, surface reaction enables PSCs with enhanced thermal and operational stability; these devices retain over 95 % of their initial PCE after damp-heat tests (i.e., in 85 °C and 85 % R. H. air) for 2000 h, and remain 99 % of their initial PCE after operating for 2000 h, representing one of the most stable inorganic PSCs reported so far.

Submicron-scale Au-decorated TiO2 mesoporous spheres for enhanced photon harvesting in DSSCs through near-field enhancement, light scattering, and dye loading

Light harvesting materials are crucial for capturing the sunlight in a device such as a solar cell for better efficiency. In this study, we developed high surface area, submicron-sized TiO2 spheres (MTS) incorporated with anisotropic Au nanoparticles (Au_MTS) to create highly light-absorbing photoanodes for enhanced dye-sensitized solar cell (DSSC) efficiency. The high surface area of MTS (∼125 m2/g) allows for increased dye-loading, while their submicron size (150–300 nm) provides superior light-scattering capabilities for significantly enhancing the photoanode’s light absorption. Furthermore, incorporating of anisotropic Au nanoparticles enables broadband surface plasmon resonance (SPR) coupling, synergistically boosting photon harvesting in the Au_MTS photoanodes. The interconnected tiny TiO2 nanoparticle network in MTS supports charge carrier generation and transport, providing ample sites for dye adsorption and efficient electron pathways. Au_MTS with varying amounts of Au nanoparticles synthesized by a greener microwave-assisted synthesis method and DSSC devices were fabricated and compared with devices made from pristine MTS and P25 nanoparticles. The optimal Au_MTS device, containing ∼1.3 wt% Au nanoparticles, achieved a maximum power conversion efficiency (PCE) of ∼7.7%, representing improvements of ∼40% and ∼60% over pristine MTS (PCE of ∼5.2%) and P25 nanoparticles (PCE of ∼4.71%), respectively. Overall, this work demonstrates the effectiveness of plasmonic mesoporous photoanodes in enhancing DSSC performance through improved photo response, light scattering, and dye loading.

Non-toxic Bi2S3 quantum dot-sensitized TiO2 electrodes for cost-efficient solar power conversion

Inorganic light harvesting materials are revolutionising the current research scope of quantum dot-sensitized solar cells (QDSSCs) day by day. However, it is challenging due to the issues in toxicity and stability of existing light-harvesting materials. Herein, we present highly stable non-toxic bismuth trisulfide (Bi2S3) QDSSCs with iodide/triiodide redox electrolyte. The solar cell is configured as FTO/TiO2 P90/TiO2 P25/Bi2S3/(I-/I-3) electrolyte/Pt. Bi2S3 quantum dots (QDs) were fabricated onto the FTO/TiO2 P90/TiO2 P25 electrode at room temperature using the dip-successive ionic layer adsorption reaction (Dip-SILAR), which is an easy and efficient technique. Electron microscopy confirmed that the quantum dots formed uniformly on the photoanode, with sizes ranging from 50 nm to 80 nm. QDSSCs with an active cell area of 0.16 cm2 were characterized under an illumination of 100 mW cm-2 with AM 1.5 spectral filter and the results depicted that the best cell acquired a power conversion efficiency of 0.26 % with an open circuit voltage (Voc) of 482.9 mV and short circuit current density (Jsc) of 1.05 mA cm-2. To enhance the stability, polyvinylpyrrolidone (PVP) based gel polymer electrolyte has been used. The high cost of conventional light harvesting materials may be significantly reduced by one-step fabrication of Bi2S3 using the SILAR technique.

Performance analysis and optimization of SnSe thin-film solar cell with Cu2O HTL through a combination of SCAPS-1D and machine learning approaches

Tin selenide (SnSe) is an auspicious light-harvesting material in photovoltaic (PV) technology due to its larger absorption coefficients and earth-abundance nature. However, because of the potential difficulty of defect-free fabrication, and non-optimized electron transport layer (ETL) and hole transport layer (HTL) alignment, it could no longer achieve its realistic objectives. Therefore, designing a suitable SnSe-based PV device with an appropriate ETL and HTL is crucial to achieving optimum performance. In this research, we proposed a novel heterojunction thin-film solar cell (TFSC) configuration of Ni/Cu2O/SnSe/WS2/FTO/Al and simulated its PV performance metrics using SCAPS-1D solar cell simulation software. This research additionally provided a comparative performance analysis of the SnSe TFSC with numerous ETLs and HTLs. It is evident that the suggested TFSC with WS2 ETL and Cu2O HTL creates appropriate band alignment with the SnSe light harvesting layer, which reduces charge recombination at both the ETL/absorber and absorber/HTL interfaces. Here, the impact of absorber layer thickness, doping concentration, bulk defect density, and defect density at the ETL/absorber and absorber/HTL interfaces is investigated. Besides, the impact of radiative recombination, back contact metal work function, and working temperature are carefully examined. After optimization of all the material properties, a maximum efficiency of 29.31 % with open circuit voltage (Voc) of 0.89 V, short circuit current density (Jsc) of 38.23 mA/cm2, and fill-factor (FF) of 86.30 % were attained for the SnSe-based proposed structure. Furthermore, a supervised linear regression machine learning algorithm is employed to investigate how the behavior of the material attributes affects the solar cell's designed PV performance. Overall, our findings can be helpful to experimentalists to fabricate inexpensive, highly efficient, and Cd-free SnSe-based heterostructure solar cells in the near future.

The Development of Metal-Free Porous Organic Polymers for Sustainable Carbon Dioxide Photoreduction.

A viable tactic to effectively address the climate crisis is the production of renewable fuels via photocatalytic reactions using solar energy and available resources like carbon dioxide (CO2) and water. Organic polymer material-based photocatalytic materials are thought to be one way to convert solar energy into valuable chemicals and other solar fuels. The use of porous organic polymers (POPs) for CO2 fixation and capture and sequestration to produce beneficial compounds to reduce global warming is still receiving a lot of interest. Visible light-responsive organic photopolymers that are functionally designed and include a large number of heteroatoms and an extended π-conjugation allow for the generation of photogenerated charge carriers, improved absorption of visible light, increased charge separation, and decreased charge recombination during photocatalysis. Due to their rigid structure, high surface area, flexible pore size, permanent porosity, and adaptability of the backbone for the intended purpose, POPs have drawn more and more attention. These qualities have been shown to be highly advantageous for numerous sustainable applications. POPs may be broadly categorized as crystalline or amorphous according to how much long-range order they possess. In terms of performance, conducting POPs outperform inorganic semiconductors and typical organic dyes. They are light-harvesting materials with remarkable optical characteristics, photostability, cheap cost, and low cytotoxicity. Through cocatalyst loading and morphological tweaking, this review presents optimization options for POPs preparation techniques. We provide an analysis of the ways in which the preparative techniques will affect the materials' physicochemical characteristics and, consequently, their catalytic activity. An inventory of experimental methods is provided for characterizing POPs' optical, morphological, electrochemical, and catalytic characteristics. The focus of this review is to thoroughly investigate the photochemistry of these polymeric organic photocatalysts with an emphasis on understanding the processes of internal charge generation and transport within POPs. The review covers several types of amorphous POP materials, including those based on conjugated microporous polymers (CMPs), inherent microporosity polymers, hyper-crosslinked polymers, and porous aromatic frameworks. Additionally, common synthetic approaches for these materials are briefly discussed.

Enhanced Phase Stability and Reduced Bandgap for CsPbI3 Perovskite through Bi3+ and Cl– Co-Doping

All-inorganic perovskite CsPbI3 is emerging as a thermally more stable alternative to organic-inorganic hybrid perovskites. However, CsPbI3 perovskite suffers from poor phase stability at ambient temperature, and its bandgap is a bit too large as light-harvesting materials in both single-junction and perovskite-on-silicon tandem solar cells. In this study, we propose an electrically neutral co-doping strategy that equimolar Bi3+ (occupying the Pb site) and Cl– (occupying the interstitial site) are incorporated into CsPbI3. Unlike the individual Bi3+ or Cl– doping, the neutral co-doping can avoid stimulating the formation of the detrimental native defects. Our first-principles calculations suggest that the co-doped systems are stable at ambient temperature and possess narrower bandgaps compared with the undoped CsPbI3. Moreover, the electron and hole states are spatially separated in these multiple-ion compounds.

Porphyrin-based nanoporous materials for photocatalytic applications

Alongside the unique photophysical properties, porphyrin derivatives play key roles in light harvesting of photosynthetic organisms. Due to their symmetrical structure, porphyrin derivatives serve as excellent building blocks for various porous materials, encompassing metal-organic frameworks, covalent organic frameworks, hydrogen-bonded organic frameworks, and amorphous porous organic polymers. These materials capitalize on the beneficial characteristics of porphyrins, such as their absorption capabilities, redox activity, and coordination chemistry, while leveraging the surface area and porosity inherent in porous frameworks. Porphyrin-based porous materials are explored for diverse applications including gas storage, energy storage, catalysis, separation, sensing, and environmental remediation. Owing to their excellent photophysical properties, these nanoporous materials are suitable for light harvesting and photocatalysis applications. This review emphasizes the potential of artificial light-harvesting catalysts based on porphyrin-based porous materials for solar energy applications. Researchers aim to optimize material properties and design innovative architectures to enhance performance in solar energy conversion and photocatalytic applications, making this a rapidly evolving field. Specific applications discussed in the review include photocatalytic CO2 reduction, photocatalytic water splitting, and perspectives on future developments in the field of porphyrin-based nanoporous materials for artificial light harvesting.

Light-Induced Redox Dynamics in Plasmonic Nanostructures and Photosensitizer Transition Metal Compounds

Solar energy harvesting is a nuanced scientific field that involves precise control across energy, time, and nanometer length scales. The understanding of how to harness sunlight to promote chemical reactions is vital for the advancement of renewable energy applications and a sustainable future. Limited knowledge of the precise chemical mechanisms underlying solar energy harvesting restricts widespread technological use and the development of photovoltaic devices that utilize light-harvesting biodegradable materials. My research focuses on developing a fundamental understanding of visible light-activated excited state chemistry that is of great importance in elucidating the mechanisms, structures, and design features for catalysis. In this talk, we will examine excited-state chemical structure dynamics in nanomaterials that use light-matter interactions to drive interfacial or intramolecular charge transfer. Steady-state and time-resolved optical/X-ray spectroscopy allow for the observation of these dynamics across an expansive timescale—from the seconds timescale of oxygen-evolving reactions to the ultrafast timescales of electronic and vibrational motion. Novel light-matter interactions in plasmonic nanostructures, biomimetic metal oxides, and molecular transition metal complexes will be discussed. The talk will conclude with future opportunities for expanding the scope of nanoscale photocatalysis and for designing enhanced localized control over excited-state chemistry.[1] E. A. Sprague-Klein*, X. He, M. W. Mara, B. J. Reinhart, S. Lee, L. M. Utschig, K. L. Mulfort, L. X. Chen*, D. M. Tiede*. “Photo-Electrochemical Effect in the Water Oxidation Catalyst Cobalt-Phosphate (CoPi),” ACS Energy Letters, 2022, 7, 9, 3129–3138. [2] N. L. Warren, U. Yunusa, A. B. Singhal, E. A. Sprague-Klein*. "Facilitating Excited-State Plasmonics and Photochemical Reaction Dynamics," Chemical Physics Reviews, (Accepted December 2023).[3] U. Yunusa, N. Warren, D. Schauer, P. Srivastava, E. Sprague-Klein*. "Plasmon resonance dynamics and enhancement effects in Tris(bipyridine)ruthenium(II) gold nanosphere oligomers," Nanoscale, (Under Review).

(Invited) Porous Crystalline Frameworks as Intrinsic Photocatalytic Materials

Porous crystalline materials such as metal organic frameworks (MOFs) and covalent organic frameworks (COFs) represent a novel class of materials for catalysis due to their inherent porous nature, exceptional thermal and chemical stability, structural flexibility. While many photocatalytic systems based on these materials have been developed in the past decade, a significant gap exists in our understanding of the correlation of photophysical and photocatalytic properties of MOFs/COFs with their structure, which hinders accurate prediction and informed design. We aim to address this challenge using an interdisciplinary approach that combines innovative material design and synthesis, fundamental mechanistic studies, theoretical prediction, and photocatalytic performance evaluation. In this talk, I will discuss our recent progress in developing porous crystalline materials as intrinsic light harvesting materials and heterogenous catalysts for solar fuel generation.

One-Step Hydrothermal Deposition of AgSbS2-xSex Thin Films for Solar Cell Applications.

AgSbS2-xSex is a promising light-harvesting material for thin film solar cells, characterized by nontoxicity, high chemical stability, and excellent optoelectronic properties. However, the complex chemical composition of AgSbS2-xSex poses significant challenges to thin film preparation, giving rise to an intensive dependence on multi-step preparation methods. Herein, a hydrothermal method is developed for depositing AgSbS2-xSex films and achieves one-step preparation of this kind of thin film materials for the first time. This method can provide sufficient energy for atomic nucleation and adsorption on the substrate surface to promote nuclei aggregation and grow into films. Meanwhile, it achieves control of the chemical kinetics of the deposition solution by introducing EDTA-2Na as an additive and suppressing the enrichment of Ag2Se impurities at the substrate interface. As a result, a high-purity AgSbS2-xSex film with compact and flat morphology is prepared and assembled into solar cells. The device delivers a power conversion efficiency of 3.04% under standard illumination, which is currently the highest efficiency for AgSbS2-xSex solar cells fabricated by the one-step method. This study provides a facile and promising method for the controllable preparation of high-quality AgSbS2-xSex thin films and promoting their application in solar cells.

Full optoelectronic simulation of all antimony chalcogenide thin film tandem solar cell: Design routes from 4-T to 2-T configuration

Antimony chalcogenide, as a newcomer to light harvesting materials, is regarded as an auspicious contender for incorporation as a photoactive layer in thin film tandem solar cells (TFTSCs). The current study introduces the design of all-antimony chalcogenide TFTSC comprised of an Sb2S3 (1.7 eV) front subcell and an Sb2Se3 (1.2 eV) rear subcell. The challenges to migrating from four-terminal (4-T) to two-terminal (2-T) designs are highlighted and possible solutions are proposed. To commence, a calibration procedure for the two subcells is conducted in alignment with experimental investigations. The benchmarked solar cells yield a power conversion efficiency (PCE) of 8.08 % for the upper subcell and 10.58 % for the lower subcell. Subsequently, upon integration of both subcells within the initial 4-T Sb2S3/Sb2Se3 TFTSC, the resultant PV cell attains a PCE of 12.27 %. Before transitioning it to a more efficient 2T tandem configuration, we explore alternative inorganic HTL materials to the Spiro-OMeTAD HTL to overcome its practical considerations. Cu2O is found to be the best HTL alternative to be included for both subcells. Upon stacking into the tandem structure, the combined cell exhibited an efficiency of 15.68 % and a notable Jsc of 16.23 mA/cm2. To further enhance the tandem performance, the device structure is optimized by engineering the CBO of two sub-cells and employing a double ETL design for the front sub-cell. At the considered current matching criterion, the tandem device PCE and Jsc are boosted to 27.86 % and 17.60 mA/cm2, respectively. Based on this full optoelectronic analysis, developed in the Silvaco TCAD environment, a 2-T all antimony chalcogenide tandem configuration can be realized and optimized, paving the way for future experimental endeavors.

Room-temperature phosphorescence from organic materials in aqueous media.

In recent years, organic materials with room-temperature phosphorescence (RTP) features have gained significant attention due to their wide applications in the fields of bioimaging, light-harvesting materials, encryption technology, etc. Although several examples of organic RTP materials in the crystalline state and polymer-based systems have been reported in the last decade or so, achieving organic RTP in the solution phase, particularly in the aqueous phase has remained a challenging task. Herein in this review, we summarize the progress in this direction by highlighting design strategies based on supramolecular scaffolding and host-guest complexation and the applications of such aqueous organic RTP materials in bioimaging, sensing, etc.

Active Passivation of Anion Vacancies in Antimony Selenide Film for Efficient Solar Cells.

Binary antimony selenide (Sb2Se3) is a promising inorganic light-harvesting material with high stability, nontoxicity, and wide light harvesting capability. In this photovoltaic material, it has been recognized that deep energy level defects with large carrier capture cross section, such as VSe (selenium vacancy), lead to serious open-circuit voltage (VOC) deficit and in turn limit the achievable power conversion efficiency (PCE) of Sb2Se3 solar cells. Understanding the nature of deep-level defects and establishing effective method to eliminate the defects are vital to improving VOC. In this study, a novel directed defect passivation strategy is proposed to suppress the formation of VSe and maintain the composition and morphology of Sb2Se3 film. In particular, through systematic study on the evolution of defect properties, the pathway of defect passivation reaction is revealed. Owing to the inhibition of defect-assisted recombination, the VOC increases, resulting in an improvement of PCE from 7.69% to 8.90%, which is the highest efficiency of Sb2Se3 solar cells prepared by thermal evaporation method with superstrate device configuration. This study proposes a new understanding of the nature of deep-level defects and enlightens the fabrication of high quality Sb2Se3 thin film for solar cell applications.

Multimodular Wide-Band Capturing Nanohybrids: Role of Carbon Nanotubes in Slowing Charge Recombination in Supramolecular C60-BisstyrylBODIPY-(Zinc Porphyrin)2 Donor-Acceptor Molecular Cleft.

The importance of diameter-sorted single-wall carbon nanotubes (SWCNTs) noncovalently bound to a donor-acceptor molecular cleft, 1, in prolonging the lifetime of charge-separated states is successfully demonstrated. For this, using a multistep synthetic procedure, a wide-band capturing, multimodular, C60-bisstyrylBODIPY-(zinc porphyrin)2, molecular cleft 1, was newly synthesized and shown to bind diameter-sorted SWCNTs. The molecular cleft and its supramolecular assemblies were characterized by a suite of physicochemical techniques. Free-energy calculations suggested that both the (6,5) and (7,6) SWCNTs bound to 1 act as hole acceptors during the photoinduced sequential electron transfer events. Consequently, selective excitation of 1 in 1:SWCNT hybrids revealed a two-step electron transfer, leading to the formation of charge-separated states. Due to the distant separation of the cation and anion radical species within the supramolecules, improved lifetimes of the charge-separated states could be achieved. The present supramolecular strategy of improving charge separation involving SWCNTs and donor-acceptor molecular clefts highlights the potential application of these hybrid materials for various light energy harvesting and optoelectronic applications.

Chiroptically active copper clusters as platform for enantioselective detection of lysine.

Metal clusters have drawn considerable research attention over the years due to their fascinating optical properties. Owing to their appealing photophysical characteristics, these materials have drawn attention as potential candidates for various application in diverse fields, including disease detection, biosensing, chemical sensing, and the fabrication of light-harvesting materials. Presently, there is an increasing research focus on the use of clusters in biomedical research, both as biodetection platform and as bioimaging agents. Of special interest are chiral clusters, which can selectively interact with chiral biomolecules owing to their optical activity. Herein, we showcase the use of a pair of chiroptically active copper clusters for the enantioselective detection of lysine, an amino acid of vast biological relevance. Two techniques are concurrently employed for the detection of lysine at varying concentrations. Circular dichroism serves as a potent tool for detecting lysine at low concentrations, whereas luminescence is effectively employed as a detection method for high analyte concentrations. The combined electronic impact of clusters and lysine resulted in the emergence of an enhanced enantioselective Cotton effect at specific wavelength.

Harnessing Pb-S Interactions for Long-Term Water Stability in Cesium Lead Halide Perovskite Nanocrystals.

Lead halide perovskite nanocrystals (LHP NCs) have garnered attention as promising light-harvesting materials for optoelectronics and photovoltaic devices, attributed to their impressive optoelectronic properties. However, their susceptibility to moisture-induced degradation has hindered their practical applications. Despite various encapsulation strategies, challenges persist in maintaining their stability and optoelectronic performance simultaneously. Here, a ligand exchange approach is proposed using (11-mercaptoundecyl)-N,N,N-trimethylammonium bromide (MUTAB) to enhance the stability and dispersibility of CsPbBr3 (CPB) NCs in aqueous environments. MUTAB enables effective surface passivation of the CPB NCs via robust Pb-S interactions at the S-terminal while concurrently directing water molecules through the unbound cationic N-terminal or vice versa, ensuring water dispersibility and stability. Spectroscopic analysis confirms retained structural and optical integrity post-ligand exchange. Crucially, MUTAB-bound CPB NCs exhibit sustained charge transfer properties, demonstrated by aqueous colloidal oxidation reactions. This ligand exchange strategy offers a promising pathway for advancing LHP NCs toward practical optoelectronic and photocatalytic applications.

Tuning Optical Properties of Plasmonic Aerosols through Ligand-Solvent Interactions.

Plasmonic nanoparticles are highly tunable light-harvesting materials with a wide array of applications in photonics and catalysis. More recently, there has been interest in using aerosolized plasmonic nanoparticles for cloud formation, airborne photocatalysts, and molecular sensors, all of which take advantage of the large scattering cross sections and the ability of these particles to support intense local field enhancement ("hot spots"). While extensive research has investigated properties of plasmonic particles in the solution phase, surfaces, and films, aerosolized plasmonics are relatively unexplored. Here, we demonstrate how the capping ligand, suspension solvent, and atomization conditions used for aerosol generation control the steady-state optical properties of aerosolized Silica@Au plasmonic nanoshells. Our experimental results, supported with spectral simulations, illustrate that ligand coverage and atomization conditions control the degree of solvent retention and thus the spectral characteristics and potential access to surfaces for catalysis in the aerosol phase, opening a new regime for tunable applications of plasmonic metamaterials.

Balancing Flexible Side Chains on 2D Conjugated Acceptors Enables High-Performance Organic Solar Cell.

Balancing the rigid backbones and flexible side chains of light-harvesting materials is crucially important to reach optimized intermolecular packing, micromorphology, and thus photovoltaic performance of organic solar cells (OSCs). Herein, based on a distinctive CH-series acceptor platform with 2D conjugation extended backbones, a series of nonfullerene acceptors (CH-6F-Cn) are synthesized by delicately tuning the lengths of flexible side chains from n-octyl to n-amyl. A systemic investigation has revealed that the variation of the side chain's length can not only modulate intermolecular packing modes and crystallinity but also dramatically improve the micromorphology of the active layer and eventual photovoltaic parameters of OSCs. Consequently, the highest PCE of 18.73% can be achieved by OSCs employing D18:PM6:CH-6F-C8 as light-harvesting materials.