Crystalline Density Research Articles

ZnO Nanorods Aligned in a Vertical Configuration for Targeted Electrochemical Detection of Aniline.

This study demonstrates the synthesis of 1D surface vertically aligned nanorods of ZnO on the fluorine-doped tin oxide-coated glass substrate (ZnO-VANRs/FTOs) synthesized via a chemical route for the targeted electrochemical sensing of aniline. The ZnO-VANRs/FTOs were 1.57 ± 0.03 μm in length with excellent crystallinity and high density (1.52 × 1013 rod no./m2). ZnO-VANRs formation increased surface roughness by 2.4- and 4.7-fold compared to the bare FTOs and seeded FTOs (ZnO-seed/FTOs), respectively. The ZnO-VANRs/FTOs electrodes could increase the effective surface area from 0.154 to 0.384 cm2 with about 86.85% reduction in charge transfer resistance compared to the bare FTOs. The peak current response (at 0.281 V vs Ag/AgCl) of aniline deposition was boosted by 81.52% with the rise in temperature from 15 to 45 °C. The reduction of aniline at ZnO-VANRs/FTOs involved a reversible two-electron diffusion control process with a heterogeneous reaction rate constant (k0) of 1.82 s-1 and a formal potential (E0) of 0.289 V vs Ag/AgCl. The ZnO-VANRs/FTOs electrode showed limits of detection of 0.193 μM (sensitivity 0.198 μA·μM-1·cm-2) and 0.588 μM (sensitivity of 0.065 μA·μM-1·cm-2) between the working ranges of 0-20 and 20-160 μM, respectively. The fabricated sensor was unprecedently selective toward aniline sensing, and p-nitroaniline, chlorobenzene, chlorpyrifos, Cu2+, Pb2+, Ni2+, Cd2+, albumin bovine, Escherichia coli, and ciprofloxacin could not interfere with aniline sensing and its sensitivity. However, the peak current was marginally decayed by 2.63% up to the 6th cycle. Moreover, ZnO-VANRs/FTOs catalyzed the sensing of aniline spiked in the environmental matrices, conforming well to liquid chromatography.

Enhancing photovoltaic performance and stability of inverted perovskite solar cells via multifunctional molecular additive

The film quality of perovskite absorber plays a fundamental role in determining the efficiency and stability of perovskite solar cells (PSCs), of which high crystallinity and low defect density are consistently persuaded. Here, a strategy using multifunctional additive of N,N′-Diallyl-L-tartardiamide (NDT) to produce high-quality perovskite film is proposed. The rich coordination and hydrogen bonding between NDT and perovskite effectively passivate trap states, improve film crystallinity, stabilize perovskite crystal structure and confine ions migration, resulting in enhancement of charge transport and suppression of nonradiative recombination. Consequently, compared with the control device (19.07 %), the NDT-modified devices achieve a champion efficiency of 21.71 % with negligible hysteresis as well as excellent air and light stability. This work presents a facile and effective approach via multifunctional molecular additive to achieve high-performance inverted (p-i-n) PSCs.

Indirect Enhancement of ALD Thin-Film Properties Induced by the ECAP Modification of an As-Extruded Mg-Ca Alloy.

The purpose of this study is to investigate the indirect effects on the properties of ZrO2 films deposited by atomic layer deposition (ALD) when an Mg-Ca alloy is modified through equal-channel angular pressing (ECAP) following extrusion. The study aims to understand how the increase in CaO content in the native oxide layer of the Mg-Ca alloy influences the crystallinity and defect density of the ZrO2 film. Consequently, the corrosion protection performance of the ZrO2 film is enhanced by 1.2 to 1.5 times. A reduction in the anti-scratch property of the ZrO2 film was also observed, with a critical load reduction of 34 μN. This research provides a detailed analysis of the modifications induced by ECAP on the as-extruded Mg-Ca alloy and its subsequent impact on the properties of the ZrO2 film.

Tailored molecular for ultra-stability and biocompatible pseudohalide metal-free perovskite towards X-ray detectors with record sensitivity

The emerging pseudohalide metal-free perovskite (pseudohalide–MFPs) X-ray detector caters to the demands of timely mobile diagnosis owing to its lightweight, flexibility, and cost-effectiveness. However, the performance of these devices is severely limited by poor X-ray absorption, ultra-wide band gap, relative instability, and their unknown biotoxicity. Herein, we construct heavy atom covalent bonds (C–Br/Cl) on the A-site organic cation to reinforce component coordination to modulate X-ray absorption and band gap in pseudohalide–MFPs and further enhance its stability. Molecular dynamics simulations demonstrate that the introduction of halogen atoms can strengthen hydrogen bonding interactions, thereby improving the coordination between different components. The resultant (MDABCOBr)–NH4(BF4)3 (MDABCO = N-methyl-N’-diazabicyclo[2.2.2]octonium) single crystal significantly increases X-ray absorption cross-section and crystalline density (from 1.728 to 1.950 g cm−3), and synergistically realizes the band nature modulation (from 7.4 to 5.5 eV) and enhanced ionic migration inhibition (628 meV) with optimized stability. As such, our X-ray detectors realized a sensitivity of 2377 μC Gyair−1 cm−2, an ultralow detection limit of 50.1 nGyair s−1, and impressive operation stability. Moreover, cytotoxicity assay confirmed the compatibility of pseudohalide metal-free perovskite. Finally, within this framework, we successfully fabricate the (MDABCOBr)–NH4(BF4)3-based flexible device to create an ideal in vitro wearable X-ray detection.

Anethole Regulated Crystallization for High Efficiency Carbon‐Based Perovskite Solar Cells

AbstractTwo‐step sequential deposition is a widespread technique for the fabrication of perovskite films, renowned for its better control of the crystallization process. However, achieving a well‐controlled and complete reaction of PbI2 by organic ammonium salts remains a key challenge. Previous studies have predominantly focused on regulating the properties of the PbI2 layer while paying less attention to the high reactivity of organic ammonium salts. In this study, the natural molecule anethole is first explored to control perovskite crystallization during two‐step sequential deposition, focusing on the reactivity modulation of organic formamidine ion (FA+). It is demonstrated that FA+ exhibits strong hydrogen bond interactions with anethole, inhibiting the high reactivity of FA+ and effectively delaying the rapid reaction between FAI and PbI2. This decelerates the crystallization kinetics of perovskite films, facilitating the orderly and complete reaction of PbI2 by FAI while suppressing detrimental δ‐phase formation. Consequently, FA‐based perovskite films with high crystallinity, preferred orientation, and low defect state density are obtained. The fabricated planar hole transport layer‐free carbon electrode perovskite solar cells deliver an efficiency of 20.41% (certified efficiency of 20.0%), which is a new record for this kind of solar cell.

Near-infrared Spectroscopy for Remote Sensing of Porosity, Density, and Cubicity of Crystalline and Amorphous H2O Ices in Astrophysical Environments

We present laboratory spectra of pure amorphous and crystalline H2O ices in the near-infrared (NIR, 1–2.5 μm/10,000–4000 cm−1) at 80–180 K. The aim of this study is to provide spectroscopic reference data that allow remotely accessing ice properties for icy objects such as icy moons, cometary ice, or Saturn rings. Specifically, we identify new spectral markers for assessing three important properties of ices in space: (i) porosity/fluffiness, (ii) bulk density of amorphous ice, and (iii) cubicity in crystalline ice. The analysis is based on the first OH-stretching overtone (2ν OH) and the combinational band at 5000 cm−1/2 μm, which are potent spectral markers for these properties. By comparison of vapor-deposited, microporous amorphous solid water, pore-free low-, high-, and very-high-density amorphous ice, we are able to separate the effect of (bulk) density from the effect of porosity on NIR-spectra of amorphous ices. This allows for clarifying a longstanding inconsistency about the density of amorphous ice vapor-deposited at low temperatures, first brought up by Jenniskens & Blake. Direct comparison of NIR spectra with powder X-ray diffractograms allows us to correlate spectral features with the number of cubic stacking layers in stacking-disordered ice Isd, ranging from fully cubic ice Ic to fully hexagonal ice Ih. We show that exposure times for instruments on the James Webb Space Telescope are in the hour range to distinguish these properties, demonstrating the usefulness of the neglected NIR spectral range for identifying ices in space.

Multifunctional Hydroxylamine‐O‐Sulfonic Acid as Additives for Highly Efficient and Stable Perovskite Solar Cells

Despite the rapid development of perovskite solar cells (PSCs), defects in the devices continue to impede further improvements in power conversion efficiency and operational stability. In this work, the use of hydroxylamine‐O‐sulfonic acid as a bifunctional molecule to enhance the performance of PSCs is described. Strong coordination exists between the sulfonic acid group and uncoordinated Pb2+ of perovskite, while the NH bond on amino group interacts with uncoordinated I−. Thus, due to the synergistic contribution of sulfonic acid group and amino groups, the high‐quality perovskite film with good crystallinity and low defect density is achieved. As a result, the optimal devices exhibit an enhanced efficiency of 23.33%, which is much higher than that of the control device (21.53%). Notably, the optimized target device exhibits excellent long‐term operational stability, retaining over 90% of its initial efficiency after 480 h at 65 °C, over 93% after a continuous illumination test for 650 h, and over 96% after nearly 1400 h of air storage. In contrast, the control device demonstrates poorer stability. In these results, it is suggested that selecting a dual‐functional additive is a promising approach to enhance efficiency and maintain stability in PSCs.

Formation and Application of Starch–Polyphenol Complexes: Influencing Factors and Rapid Screening Based on Chemometrics

Understanding the nuanced interplay between plant polyphenols and starch could have significant implications. For example, it could lead to the development of tailor-made starches for specific applications, from bakinag and brewing to pharmaceuticals and bioplastics. In addition, this knowledge could contribute to the formulation of functional foods with lower glycemic indexes or improved nutrient delivery. Variations in the complexes can be attributed to differences in molecular weight, structure, and even the content of the polyphenols. In addition, the unique structural characteristics of starches, such as amylose/amylopectin ratio and crystalline density, also contribute to the observed effects. Processing conditions and methods will always alter the formation of complexes. As the type of starch/polyphenol can have a significant impact on the formation of the complex, the selection of suitable botanical sources of starch/polyphenols has become a focus. Spectroscopy coupled with chemometrics is a convenient and accurate method for rapidly identifying starches/polyphenols and screening for the desired botanical source. Understanding these relationships is crucial for optimizing starch-based systems in various applications, from food technology to pharmaceutical formulations.

Synchronous effect of coordination and hydrogen bonds boosting the photovoltaic performance of perovskite solar cells

Superior quality of perovskite film with perfect crystalline and low defect density is crucial for achieving excellent photovoltaic performance and durability of perovskite solar cells (PSCs), and regulation of growth of perovskite crystal and defects passivation by additive is remain challenge. Herein, two acyl molecules (Succinimide: SCI, and Hydantoin: HDT) were incorporated into perovskite precursor solution as additive. It can be found that the HDT molecule can not only passivate undercoordinated Pb2+ defects in perovskite films by the -C=O groups with coordination bonds, but also formed hydrogen bonds with I− by -NH- group, which effectively inhibited the formation of iodine vacancy defects and regulated growth rate of perovskite crystals, and the quality of perovskite films was optimized with enlarging grain size and reduced trap-density. Consequently, power conversion efficiency of HDT-based device was enhanced from 19.47 % to 21.00 %, with an enhancement of JSC and VOC. Moreover, the HDT-based device without encapsulation retained 83.7 % of its initial PCE after being aged at 10–20 % RH for 60 days. Obviously, such a study could provide a new strategy to optimize quality of perovskite film for boosting performance of PSCs.

In‐situ elemental reaction‐regulated Ag2S films enable the best thermoelectric performances

AbstractSilver sulfide thin film, with excellent thermoelectric properties, is few reported due to the complex and time‐consuming high‐temperature or high‐pressure synthesis process. Here, a fast ionic conductor n‐type Ag2S film with good crystallinity and uniform density is prepared by sputtering metal Ag films of different thicknesses on glass and then reacting in S precursor solution at low temperature. At 450 K, β‐Ag2S films can be obtained and underwent a phase transition from α‐Ag2S monoclinic, which had a significant effect on their electrical and thermal properties. The grain size of Ag2S films increases with the increase of film thickness. Before and after the phase transition, the carrier concentration and mobility cause obvious changes in the electrical properties of Ag2S. The carrier concentration of body‐centered cubic phase β‐Ag2S is about three orders of magnitude higher than that of monoclinic phase α‐Ag2S, and the mobility is also 2–3 times that of the latter. Especially, after the phase transition, the conductivity of β‐Ag2S rises exponentially from the zero conductivity of α‐Ag2S and increases with the increase of temperature. The Ag2S film shows the highest figure of merit of 0.83 ± 0.30 at 600 K from the sample with ∼1600 nm thickness, which is the highest record among Ag2S‐based thermoelectric materials reported so far.

Correlation of Dysfunctional Lens Index with Lens Opacification System III in Age Related Cataract

Purpose: Age-Related changes in crystalline lens opacity and lens density contribute to formation of higher order aberrations resulting in reduced quality of vision. Precise quantification of cataract is important for predicting phacodynamics and educating patient. The iTrace(a ray-tracing aberrometer) provides Dysfunctional Lens Index (DLI). This study from Pakistan investigates the relationship between LOCS III and DLI in senile cataract. Study Design: Correlational study. Place and Duration of Study: Hashmanis Hospital, Karachi from March 2021 to May 2021. Methods: This study included 44 patients with age-related cataract. Demographic characteristics and complete ophthalmic examination of eyes including Best Corrected Visual Acuity (BCVA) and slit lamp biomicroscopy were performed. Age related cataracts were graded using the Standard technique of LOCS III. I-Trace was utilized for wave front analysis to calculate DLI. Results: BCVA and LOCS III nuclear opalescence score had strongest positive linear correlation (r=0.433, P<0.01). DLI displayed a strong significant negative correlation to LOCS III Cortical Cataract (C) and LOCS III Posterior Sub-Capsular Cataract (P) score (r=-0.415 and r=-0.694; respectively). Conclusion: BCVA had insignificant and small to no correlation to LOCS III C score and P score. Whereas, DLI showed the strongest significant correlation to LOCS III C score and P score. Patient's optical quality determined by visual symptoms are more closely associated to DLI parameter as compared to LOCS III classification. DLI can provide a better objective way to elevate age related cataract, monitor the progression and determine phacodynamics.

An ATP-free packaging of T4 DNA

Packaging of viral DNA into a capsid with liquid crystalline density is a crucial step in viral reproduction. DNA packaging with an adenosine triphosphate (ATP)-fueled molecular motor is an established viral DNA packaging mechanism system. On the other hand, DNA is compacted by the conformational change attributable to multivalent cations exclusively at valences higher than three. The conformational change of DNA was not considered as a mechanism of DNA packaging of viruses. Here, T4 DNA, ejected from a capsid in the ambient concentration of phosphate corresponding to the intra-cell concentration, is packaged into the capsid when the phosphate concentration decreases to the extra-cell concentration in coexistence with divalent cations, that is, Ca2+ and Mg2+. The compaction and packaging processes coincide with the conformational change of DNA. Divalent cations can compact T4 DNA when the counter anion is phosphate. The DNA-packaged and re-generated virions showed equivalent infective ability with the original populations. Fluorescent microscopy distinguished the conformational changes of DNA between compact forms and coil forms. Packaged or unpackaged DNA was confirmed enzymatically. Plaque-forming unit (Pfu) was used as the measure of infectious ability of virions. The concentration of ATP was measured by the luminometric method. The packaging process was proceeded in picomolar or lower concentration of ATP. This series of procedures may constitute a new ATP-free or low-ATP approach to packaging viral DNA with DNA conformational change underpinning the process. The results from this study may disclose an undiscovered facet of T4 life cycle.

Tailoring the aluminum nanocrystal surface oxide for all-aluminum-based antenna-reactor plasmonic photocatalysts

Aluminum nanocrystals (AlNCs) are of increasing interest as sustainable, earth-abundant nanoparticles for visible wavelength plasmonics and as versatile nanoantennas for energy-efficient plasmonic photocatalysis. Here, we show that annealing AlNCs under various gases and thermal conditions induces substantial, systematic changes in their surface oxide, modifying crystalline phase, surface morphology, density, and defect type and concentration. Tailoring the surface oxide properties enables AlNCs to function as all-aluminum-based antenna-reactor plasmonic photocatalysts, with the modified surface oxides providing varying reactivities and selectivities for several chemical reactions.

Ultra-thin CdTe film properties enhancement via eco-friendly MgCl2-assisted thermal treatment

AbstractThe thermal treatment of the CdTe thin film in the presence of CdCl2 is a crucial step in the creation of high-efficiency CdTe-based solar cells. The process influences the grain growth, grain boundary passivation, and doping, including CdTe recrystallization, and promotes to building of the photovoltaic junction. However, toxic Cd2+ ions released by the CdCl2, which is highly soluble in water is a major environmental concern of this process. Also, the price of CdCl2 (about 30 cents/gram) that drives up manufacturing costs is another limitation of the current processs. Finding a non-toxic Cl molecule is therefore currently in high demand and key factor for the thermal treatment of CdTe. In this study, MgCl2 was thoroughly explored as an alternative, non-toxic, and somewhat less expensive chlorine-containing chemical for CdTe thermal treatment. CdTe thin films, approximately 1.0 µm thick, were deposited on a glass substrate at 350 ºC using RF magnetron sputtering, and after deposition, different concentrations of MgCl2 (0.2 M, 0.3 M, 0.4 M, and 0.5 M) mixed with 10% methanol were applied to the films for around 10 s, forming a thin MgCl2 coating, followed by the optimized heat treatment at 400 ºC in a nitrogen–oxygen environment. We found that the thermal treatment of CdTe films using MgCl2 showed improved crystallinity, surface morphology, impurity profiles, and carrier density similar to the conventional CdCl2 process. The sample treated with 0.4 M MgCl2 exhibited the best output as obtained the band gap of nearly 1.46 eV, a refractive index of 2.84, a carrier concentration of 9.81E+15 cm−3, and mobility 35.08 cm2/V-S with a moderate resistivity. Our findings show that MgCl2 could be utilized instead of traditional CdCl2 in the current fabrication procedure, which substantially lowers the environmental hazard with a cost-effective production process of CdTe-assembled solar cells.

Impact of crystallinity and grain density on the charge-carrier distribution and transport in organic semiconductors

The crystalline and amorphous phases often coexist in the organic active layers of their electronic devices, which further undergo morphological changes over time. Understanding of the characteristics of the microscopic processes in polycrystalline organic films is essential for optimizing organic semiconductors and their devices, particularly in the context of flexible electronics. Here, we systematically investigate the charge-carrier distributions and transport in polycrystalline organic films, focusing on the impact of the crystallinity and grain density. These polycrystalline morphology data were generated from an efficient Monte Carlo method, which were then incorporated into molecular-level device simulations that can describe the microscopic charge-transport processes. These results demonstrate the distributions and transport characteristics of charge carriers in different phases of the polycrystalline organic semiconductor films, as well as the influencing factors. Importantly, we show that the influence of a polycrystalline morphology becomes more pronounced at low driving voltages, which has been the subject of significant research efforts. Our study also revealed a decrease in mobility at low crystallinities, a phenomenon that was not previously anticipated.

Post-hot-cast annealing deposition of perovskite films with infused multifunctional organic molecules to enhance the performance of large-area light-emitting devices.

All-inorganic perovskites show great promise as an emission layer in perovskite light-emitting diodes (PeLEDs) owing to their easy solution processing, low manufacturing cost, and excellent optoelectronic properties. However, there is still an immense performance gap from small-area devices to large-area PeLED devices. The inhomogeneity of large-area high-quality perovskite films inevitably leads to vast defects and electroluminescence performance losses. Herein, a post-hot-cast annealing deposition scheme and the introduction of the multifunctional molecule 2-amino-1,3-propanediol (APDO) were proposed to regulate the crystallization of the perovskite film. As a result, uniform APDO:CsPbBr2.5Cl0.5 perovskite films with high crystallinity and lower defect density were deposited by post-hot-cast annealing. A decent maximum brightness of 2659 cd m-2 was achieved for the large-area cyan PeLEDs with an emitting area of 400 mm2.

Dioxygen-halogen bonding exemplified by crystalline peroxosolvates of N,N'-bis(haloacetyl) bispidines.

The halogen bonding in molecular crystals and supramolecular assemblies has been widely investigated. Special attention is given to the molecular structures capable of simultaneously exhibiting different types of non-covalent interactions, including conventional hydrogen bonds and halogen bonds. This paper systematically analyzes crystalline peroxosolvates of bispidine-based bis-amide derivatives, containing haloacetic acid residues, namely previously reported 1,1'-(1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-iodooethanone) peroxosolvate C13H20I2N2O2·H2O2 (1) and four new crystalline compounds, 1,1'-(1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-bromoethanone) peroxosolvate C13H20Br2N2O2·H2O2 (2), 1,1'-(9-hydroperoxy-9-hydroxy-1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-iodoethanone) peroxosolvate C13H20I2N2O5·0.5H2O2 (3), 1,1'-(9-hydroperoxy-9-hydroxy-1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-bromoethanone) peroxosolvate C13H20Br2N2O5·H2O2 (4), and 1,1'-(9-hydroperoxy-9-hydroxy-1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane-3,7-diyl)bis(2-chloroethanone) peroxosolvate C13H20Cl2N2O5·H2O2 (5). Compounds 2-5 were synthesized for the first time and their crystal structures were determined by single-crystal X-ray diffractometry (SCXRD). To the best of our knowledge, 3-5 are unprecedented crystalline hydrogen peroxide adducts of organic hydroperoxides (R-OOH). Short intermolecular contacts between halogen and hydroperoxo oxygen atoms were found in 1-3. The halogen bonding of C-I(Br) fragments with dioxygen species in compounds 1-3 as well as in the previously reported cocrystal of diacetone diperoxide with triodotrinitrobenzene (6) was identified through reduced density gradient analysis, Hirshfeld surface analysis, and Bader analysis of crystalline electron density. The interactions were quantified using the electron density topological properties acquired from the periodic DFT calculations and evaluated to lie in the range of 9-19 kJ mol-1. A distinctive spectral feature was revealed for this type of interaction, involving a red shift of the characteristic O-O stretching vibration by about 6 cm-1, which appeared in IR spectra as a narrow low-intensity band in the region 837-872 cm-1.

Hole Mobility Enhancement in Benzo[1,2-b:4,5-b']Dithiophene-Based Conjugated Polymer Transistors through Directional Alignment, Perovskite Functionalization and Solid-State Electrolyte Gating.

Tunability in electronic and optical properties has been intensively explored for developing conjugated polymers and their applications in organic and perovskite-based electronics. Particularly, the charge carrier mobility of conjugatedpolymer semiconductors has been deemed to be a vital figure-of-merit for achieving high-performance organic field-effect transistors (OFETs). In this study, the systematic hole carrier mobility improvement of benzo[1,2-b:4,5-b']dithiophene-based conjugated polymer in perovskite-functionalized organic transistors is demonstrated. In conventional OFETs with a poly(methyl methacrylate) (PMMA)gate dielectric, improvements in hole mobility of 0.019cm2V-1s-1 are measured using an off-center spin-coating technique, which exceeds those of on-center counterparts (0.22 ± 0.07 × 10-2cm2V-1s-1). Furthermore, the mobility drastically increases by adopting solid-state electrolyte gating, corresponding to 2.99 ± 1.03cm2V-1s-1 for the control, and the best hole mobility is 8.03cm2V-1s-1 (average ≈ 6.94 ± 0.59cm2V-1s-1) for perovskite-functionalized OFETs with a high current on/off ratio of >106. The achieved device performance would be attributed to the enhanced film crystallinity and charge carrier density in the hybrid perovskite-functionalized organic transistor channel, resulting from the high-capacitance electrolyte dielectric.

B-Site Co-Doping Coupled with Additive Passivation Pushes the Efficiency of Pb-Sn Mixed Inorganic Perovskite Solar Cells to Over 17.

Pb-Sn mixed inorganic perovskite solar cells (PSCs) have garnered increasing interest as a viable solution to mitigate the thermal instability and lead toxicity of hybrid lead-based PSCs. However, the relatively poor structural stability and low device efficiency hinder its further development. Herein, high-performance manganese (Mn)-doped Pb-Sn-Mn-based inorganic perovskite solar cells (PSCs) are successfully developed by introducing Benzhydroxamic Acid (BHA) as multifunctional additive. The incorporation of smaller divalent Mn cations contributes to a contraction of the perovskite crystal, leading to an improvement in structural stability. The BHA additive containing a reductive hydroxamic acid group (O═C-NHOH) not only mitigates the notorious oxidation of Sn2+ but also interacts with metal ions at the B-site and passivates related defects. This results in films with high crystallinity and low defect density. Moreover, the BHA molecules tend to introduce a near-vertical dipole moment that parallels the built-in electric field, thus facilitating charge carrier extraction. Consequently, the resulting device delivers a champion PCE as high as 17.12%, which represents the highest reported efficiency for Pb-Sn-based inorganic PSCs thus far. Furthermore, the BHA molecule provides an in situ encapsulation of the perovskite grain boundary, resulting in significant enhancement of device air stability.

Grain Crystallinity, Anisotropy, and Boundaries Govern Microscale Hydrodynamic Transport in Semicrystalline Porous Media.

Polycrystallinity is often an unintended consequence of real manufacturing processes used to produce designer porous media with deterministic and periodic architectures. Porous media are widely employed as high-surface conduits for fluid transport; unfortunately, even small concentrations of defects in the long-range order become the dominant impediment to hydrodynamic transport. In this study, we isolate the effects of these defects using a microfluidic analogy to energy transport in atomic polycrystals by directly tracking capillary transport through polycrystalline inverse opals. We reveal─using high-fidelity florescent microscopy─the boundary-limited nature of flow motions, along with nonlinear impedance elements introduced by the presence of "grain boundaries" that are separating the well-ordered "crystalline grains". Coupled crystallinity, anisotropy, and linear defect density contribute to direction-dominated flow characteristics in a discretized manner rather than traditional diffusive-like flow patterns. Separating individual crystal grains' transport properties from polycrystals along with new probabilistic data sets enables demonstrating statistical predictive models. These results provide fundamental insight into transport phenomena in (poly)crystalline porous media beyond the deterministic properties of an idealized unit cell and bridge the gap between engineering models and the ubiquitous imperfections found in manufactured porous materials.