High-viscosity driven modulation of biomechanical properties of human mesenchymal stem cells promotes osteogenic lineage.

Biomechanical cues could effectively govern cell gene expression to direct the differentiation of specific stem cell lineage. Recently, the medium viscosity has emerged as a significant mechanical stimulator that regulates the cellular mechanical properties and various physiological functions. However, whether the medium viscosity can regulate the mechanical properties of human mesenchymal stem cells (hMSCs) to effectively trigger osteogenic differentiation remains uncertain. The mechanism by which cells sense and respond to changes in medium viscosity, and regulate cell mechanical properties to promote osteogenic lineage, remains elusive. In this study, we demonstrated that hMSCs, cultured in a high-viscosity medium, exhibited larger cell spreading area and higher intracellular tension, correlated with elevated formation of actin stress fibers and focal adhesion maturation. Furthermore, these changes observed in hMSCs were associated with activation of TRPV4 (transient receptor potential vanilloid sub-type 4) channels on the cell membrane. This feedback loop among TRPV4 activation, cell spreading and intracellular tension results in calcium influx, which subsequently promotes the nuclear localization of NFATc1 (nuclear factor of activated T cells 1). Concomitantly, the elevated intracellular tension induced nuclear deformation and promoted the nuclear localization of YAP (YES-associated protein). The concurrent activation of NFATc1 and YAP significantly enhanced alkaline phosphatase (ALP) for pre-osteogenic activity. Taken together, these findings provide a more comprehensive view of how viscosity-induced alterations in biomechanical properties of MSCs impact the expression of osteogenesis-related genes, and ultimately promote osteogenic lineage.

Gas-Solid Phase Reaction Derived Silver Bismuth Iodide Rudorffite: Structural Insight and Exploring Photocatalytic Potential of CO2 Reduction.

Photocatalytic reduction of CO2 is a promising strategy to mitigate the effects of global warming by converting CO2 into valuable energy-dense products. Silver bismuth iodide (SBI) is an attractive material owing to its tunable bandgap and favorable band-edge positions for efficient CO2 photoreduction. In this study, SBI materials, including AgBi2I7, AgBiI4, Ag2BiI5, and Ag3BiI6 are first synthesized, through gas-solid reaction by controlling the stoichiometric ratio of reactants. The X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) results revealed that the distance between Ag-I is proportional to the degree of Ag ions delocalization, which occupies the vacant sites. That greatly retards the charge recombination at vacant sites. In addition, the surface potential via photo-assisted Kelvin probe force measurements of various SBI catalysts shows that Ag3BiI6 exhibits the highest surface potential change due to the rich delocalized Ag ions. This results in effective charge carrier transport and prevention of charge recombination at vacant sites. Taking the above advantages, the averaged CO and CH4 production rates for Ag3BiI6 achieved 0.23 and 0.10 µmol g-1 h-1, respectively. The findings suggest that Ag3BiI6 has a high potential as a novel photocatalyst for CO2 reduction and sheds light on the possibility of solving environmental contamination and sustainable energy crises.

Matrix mechanics regulates muscle regeneration by modulating kinesin-1 activity.

Sarcopenia, a prevalent muscle disease characterized by muscle mass and strength reduction, is associated with impaired skeletal muscle regeneration. However, the influence of the biomechanical properties of sarcopenic skeletal muscle on the efficiency of the myogenic program remains unclear. Herein, we established a mouse model of sarcopenia and observed a reduction in stiffness within the sarcopenic skeletal muscle in vivo. To investigate whether the biomechanical properties of skeletal muscle directly impact the myogenic program, we established an in vitro system to explore the intrinsic mechanism involving matrix stiffness control of myogenic differentiation. Our findings identify the microtubule motor protein, kinesin-1, as a mechano-transduction hub that senses and responds to matrix stiffness, crucial for myogenic differentiation and muscle regeneration. Specifically, kinesin-1 activity is positively regulated by stiff matrices, facilitating its role in transporting mitochondria and enhancing translocation of the glucose transporter GLUT4 to the cell surface for glucose uptake. Conversely, the softer matrices significantly suppress kinesin-1 activity, leading to the accumulation of mitochondria around nuclei and hindering glucose uptake by inhibiting GLUT4 membrane translocation, consequently impairing myogenic differentiation. The insights gained from the in-vitro system highlight the mechano-transduction significance of kinesin-1 motor proteins in myogenic differentiation. Furthermore, our study confirms that enhancing kinesin-1 activity in the sarcopenic mouse model restores satellite cell expansion, myogenic differentiation, and muscle regeneration. Taken together, our findings provide a potential target for improving muscle regeneration in sarcopenia.

Concentrated Formic Acid from CO2 Electrolysis for Directly Driving Fuel Cell.

The production of formic acid via electrochemical CO2 reduction may serve as a key link for the carbon cycle in the formic acid economy, yet its practical feasibility is largely limited by the quantity and concentration of the product. Here we demonstrate continuous electrochemical CO2 reduction for formic acid production at 2 M at an industrial-level current densities (i.e., 200 mA cm-2 ) for 300 h on membrane electrode assembly using scalable lattice-distorted bismuth catalysts. The optimized catalysts also enable a Faradaic efficiency for formate of 94.2 % and a highest partial formate current density of 1.16 A cm-2 , reaching a production rate of 21.7 mmol cm-2 h-1 . To assess the practicality of this system, we perform a comprehensive techno-economic analysis and life cycle assessment, showing that our approach can potentially substitute conventional methyl formate hydrolysis for industrial formic acid production. Furthermore, the resultant formic acid serves as direct fuel for air-breathing formic acid fuel cells, boasting a power density of 55 mW cm-2 and an exceptional thermal efficiency of 20.1 %.

Electrospun SnO2/WO3 Heterostructure Nanocomposite Fiber for Enhanced Acetone Vapor Detection.

Volatile organic compounds (VOCs), often invisible but potentially harmful, are prevalent in industrial and laboratory settings, posing health risks. Detecting VOCs in real-time with high sensitivity and low detection limits is crucial for human health and safety. The optical sensor, utilizing the gasochromic properties of sensing materials, offers a promising way of achieving rapid responses in ambient environments. In this study, we investigated the heterostructure of SnO2/WO3 nanoparticles and employed it as the primary detection component. Using the electrospinning technique, we fabricated a sensing fiber containing Ag NPs, poly(methyl methacrylate) (PMMA), and SnO2/WO3 (PMMA-Ag-SnO2/WO3) for acetone vapor detection. Following activation via UV/ozone treatment, we observed charge migration between WO3 and SnO2, resulting in a substantial generation of superoxide radicals on SnO2 nanoparticles. This phenomenon facilitates structural deformation of the fiber and alters the oxidation state of tungsten ions, ultimately leading to a significant change in extinction when exposed to acetone vapor. As a result, PMMA-Ag-SnO2/WO3 fiber achieves a detection limit of 100 ppm and a response time of 1.0 min for acetone detection. These findings represent an advancement in the development of sensitive and selective VOC sensing devices.

Development of vessel mimicking microfluidic device for studying mechano-response of endothelial cells.

The objective of this study is to develop a device to mimic a microfluidic system of human arterial blood vessels. The device combines fluid shear stress (FSS) and cyclic stretch (CS), which are resulting from blood flow and blood pressure, respectively. The device can reveal real-time observation of dynamic morphological change of cells in different flow fields (continuous flow, reciprocating flow and pulsatile flow) and stretch. We observe the effects of FSS and CS on endothelial cells (ECs), including ECs align their cytoskeleton proteins with the fluid flow direction and paxillin redistribution to the cell periphery or the end of stress fibers. Thus, understanding the morphological and functional changes of endothelial cells on physical stimuli can help us to prevent and improve the treatment of cardiovascular diseases.

Injectable Hydrogel Guides Neurons Growth with Specific Directionality.

Visual disabilities affect more than 250 million people, with 43 million suffering from irreversible blindness. The eyes are an extension of the central nervous system which cannot regenerate. Neural tissue engineering is a potential method to cure the disease. Injectability is a desirable property for tissue engineering scaffolds which can eliminate some surgical procedures and reduce possible complications and health risks. We report the development of the anisotropic structured hydrogel scaffold created by a co-injection of cellulose nanofiber (CNF) solution and co-polypeptide solution. The positively charged poly (L-lysine)-r-poly(L-glutamic acid) with 20 mol% of glutamic acid (PLLGA) is crosslinked with negatively charged CNF while promoting cellular activity from the acid nerve stimulate. We found that CNF easily aligns under shear forces from injection and is able to form hydrogel with an ordered structure. Hydrogel is mechanically strong and able to support, guide, and stimulate neurite growth. The anisotropy of our hydrogel was quantitatively determined in situ by 2D optical microscopy and 3D X-ray tomography. The effects of PLLGA:CNF blend ratios on cell viability, neurite growth, and neuronal signaling are systematically investigated in this study. We determined the optimal blend composition for stimulating directional neurite growth yielded a 16% increase in length compared with control, reaching anisotropy of 30.30% at 10°/57.58% at 30°. Using measurements of calcium signaling in vitro, we found a 2.45-fold increase vs. control. Based on our results, we conclude this novel material and unique injection method has a high potential for application in neural tissue engineering.

Electrospun Fibrous Nanocomposite Sensing Materials for Monitoring Biomarkers in Exhaled Breath.

Human-exhaled breath mainly contains water, oxygen, carbon dioxide, and endogenous gases closely related to human metabolism. The linear relationship between breath acetone and blood glucose concentration has been revealed when monitoring diabetes patients. Considerable attention has been directed toward developing a highly sensitive volatile organic compounds (VOCs) sensing material that can detect breath acetone. In this study, we propose a tungsten oxide/tin oxide/silver/poly (methyl methacrylate) (WO3/SnO2/Ag/PMMA) sensing material fabricated using the electrospinning technique. By monitoring the evolution of sensing materials' extinction spectra, low concentrations of acetone vapor can be detected. Moreover, the interfaces between SnO2 and WO3 nanocrystals construct n-n junctions, which generate more electron-hole pairs than those without such structure when the light strikes. This helps to improve the sensitivity of sensing materials when they are subjected to acetone surroundings. The established sensing materials (WO3/SnO2/Ag/PMMA) exhibit a sensing limit of 20 ppm for acetone vapor and show specificity for acetone even in ambient humidity.

Early committed polarization of intracellular tension in response to cell shape determines the osteogenic differentiation of mesenchymal stromal cells.

Within the heterogeneous tissue architecture, a comprehensive understanding of how cell shapes regulate cytoskeletal mechanics by adjusting focal adhesions (FAs) signals to correlate with the lineage commitment of mesenchymal stromal cells (MSCs) remains obscure. Here, via engineered extracellular matrices, we observed that the development of mature FAs, coupled with a symmetrical pattern of radial fiber bundles, appeared at the right-angle vertices in cells with square shape. While circular cells aligned the transverse fibers parallel to the cell edge, and moved them centripetally in a counter-clockwise direction, symmetrical bundles of radial fibers at the vertices of square cells disrupted the counter-clockwise swirling and bridged the transverse fibers to move centripetally. In square cells, the contractile force, generated by the myosin IIA-enriched transverse fibers, were concentrated and transmitted outwards along the symmetrical bundles of radial fibers, to the extracellular matrix through FAs, and thereby driving FA organization and maturation. The symmetrical radial fiber bundles concentrated the transverse fibers contractility inward to the linkage between the actin cytoskeleton and the nuclear envelope. The tauter cytoskeletal network adjusted the nuclear-actomyosin force balance to cause nuclear deformability and to increase nuclear translocation of the transcription co-activator YAP, which in turn modulated the switch in MSC commitment. Thus, FAs dynamically respond to geometric cues and remodel actin cytoskeletal network to re-distribute intracelluar tension towards the cell nucleus, and thereby controlling YAP mechanotransduction signaling in regulating MSC fate decision. STATEMENT OF SIGNIFICANCE: We decipher how cellular mechanics is self-organized depending on extracellular geometric features to correlate with mesenchymal stromal cell lineage commitment. In response to geometry constrains on cell morphology, symmetrical radial fiber bundles are assembled and clustered depending on the maturation state of focal adhesions and bridge with the transverse fibers, and thereby establishing the dynamic cytoskeletal network. Contractile force, generated by the myosin-IIA-enriched transverse fibers, is transmitted and dynamically drives the retrograde movement of the actin cytoskeletal network, which appropriately adjusts the nuclear-actomyosin force balance and deforms the cell nucleus for YAP mechano-transduction signaling in regulating mesenchymal stromal cell fate decision.

Spatial Separation of Cocatalysts on Z-Scheme Organic/Inorganic Heterostructure Hollow Spheres for Enhanced Photocatalytic H2 Evolution and In-Depth Analysis of the Charge-Transfer Mechanism.

A Z-scheme heterojunction with spatially separated cocatalysts is proposed for overcoming fundamental issues in photocatalytic water splitting, such as inefficient light absorption, charge recombination, and sluggish reaction kinetics. For efficient light absorption and interfacial charge separation, Z-scheme organic/inorganic heterojunction photocatalysts are synthesized by firmly immobilizing ultrathin g-C3 N4 on the surface of TiO2 hollow spheres via electrostatic interactions. Additionally, two cocatalysts, Pt and IrOx , are spatially separated along the Z-scheme charge-transfer pathway to enhance surface charge separation and reaction kinetics. The as-prepared Pt/g-C3 N4 /TiO2 /IrOx (PCTI) hollow sphere photocatalyst exhibits an exceptional H2 evolution rate of 8.15 mmol h-1 g-1 and a remarkable apparent quantum yield of 24.3% at 330 nm in the presence of 0.5 wt% Pt and 1.2 wt% IrOx cocatalysts on g-C3 N4 and TiO2 , respectively. Photoassisted Kelvin probe force microscopy is used to systematically analyze the Z-scheme charge-transfer mechanism within PCTI. Furthermore, the benefits of spatially separating cocatalysts in the PCTI system are methodically investigated in comparison to randomly depositing them. This work adequately demonstrates that the combination of a Z-scheme heterojunction and spatially separated cocatalysts can be a promising strategy for designing high-performance photocatalytic platforms for solar fuel production.

Surfactant Tween 20 Controlled Perovskite Film Fabricated by Thermal Blade Coating for Efficient Perovskite Solar Cells.

In recent years, additive engineering has received considerable attention for the fabrication of high-performance perovskite solar cells (PSCs). In this study, a non-ionic surfactant, polyoxyethylene (20) sorbitan monolaurate (Tween 20), was added as an additive into the MAPbI3 perovskite layer, and the thermal-assisted blade-coating method was used to fabricate a high-quality perovskite film. The Tween 20 effectively passivated defects and traps in the MAPbI3 perovskite films. Such a film fabricated with an appropriate amount of Tween 20 on the substrate showed a higher photoluminescence (PL) intensity and longer carrier lifetime. At the optimal concentration of 1.0 mM Tween 20, the performance of the PSC was apparently enhanced, and the champion PSC demonstrated a PCE of 18.80%. Finally, this study further explored and compared the effect on the device performance and ambient stability of the MAPbI3 perovskite film prepared by the spin-coating method and the thermal-assisted blade coating.

Effect of cellulose compositions and fabrication methods on mechanical properties of polyurethane-cellulose composites.

A variety of cellulose-based polymer composite materials has been developed and show different impacts on the morphologies and properties of composites. Herein, we report the morphologies and properties of composites by blending polyurethane (PU) with either ethyl cellulose (EC) or cellulose nanofiber (CNF) through either drop-casting or electrospinning process. EC is homogenously mixed with PU without microphase separation and enhanced Young's modulus of composites from 0.04 to 6.94 MPa. The CNF is heterogeneously distributed in PU/CNF composites without interference on the PU microstructure and slightly increased modulus to 0.24 MPa. While the shearing force of the electrospinning process slightly affects the PU/EC composites, it drastically enhances PU crystallinity and Young's modulus to 54.95 MPa in PU/CNF composites. A model is established to summarize the effect of cellulose additives, compositions, and processes on PU/cellulose composites, providing a comprehensive understanding for designing future cellulose composites.

Antisolvent Engineering to Enhance Photovoltaic Performance of Methylammonium Bismuth Iodide Solar Cells.

High absorption ability and direct bandgap makes lead-based perovskite to acquire high photovoltaic performance. However, lead content in perovskite becomes a double-blade for counterbalancing photovoltaic performance and sustainability. Herein, we develop a methylammonium bismuth iodide (MBI), a perovskite-derivative, to serve as a lead-free light absorber layer. Owing to the short carrier diffusion length of MBI, its film quality is a predominant factor to photovoltaic performance. Several candidates of non-polar solvent are discussed in aspect of their dipole moment and boiling point to reveal the effects of anti-solvent assisted crystallization. Through anti-solvent engineering of toluene, the morphology, crystallinity, and element distribution of MBI films are improved compared with those without toluene treatment. The improved morphology and crystallinity of MBI films promote photovoltaic performance over 3.2 times compared with the one without toluene treatment. The photovoltaic device can achieve 0.26% with minor hysteresis effect, whose hysteresis index reduces from 0.374 to 0.169. This study guides a feasible path for developing MBI photovoltaics.

Charge trapping with α-Fe2O3 nanoparticles accompanied by human hair towards an enriched triboelectric series and a sustainable circular bioeconomy.

This work reports a new approach to amending polydimethylsiloxane (PDMS) by supporting α-Fe2O3 nanoparticles (NPs), thereby generating a material suitable for use as a negative triboelectric material. Additionally, human hair exhibits a profound triboelectrification effect and is a natural regenerative substance, and it was processed into a film to be used as a positive triboelectric material. Spatial distribution of α-Fe2O3 NPs, the special surface morphologies of a negative tribological layer containing nano-clefts with controlled sizes and a valley featuring a positive tribolayer based on human hair made it possible to demonstrate facile and scalable fabrication of a triboelectric nanogenerator (TENG) presenting enhanced performance; this nanogenerator produced a mean peak-to-peak voltage of 370.8 V and a mean output power density of 247.2 µW cm-2 in the vertical contact-separation mode. This study elucidates the fundamental charge transfer mechanism governing the triboelectrification efficiency and its use in harvesting electricity for the further development of powerful TENGs suitable for integration into wearable electronics and self-charging power cells, and the work also illustrates a recycling bioeconomy featuring systematic utilization of human hair waste as a regenerative resource for nature and society.

Flexible Layered-Graphene Charge Modulation for Highly Stable Triboelectric Nanogenerator.

The continuous quest to enhance the output performance of triboelectric nanogenerators (TENGs) based on the surface charge density of the tribolayer has motivated researchers to harvest mechanical energy efficiently. Most of the previous work focused on the enhancement of negative triboelectric charges. The enhancement of charge density over positive tribolayer has been less investigated. In this work, we developed a layer-by-layer assembled multilayer graphene-based TENG to enhance the charge density by creatively introducing a charge trapping layer (CTL) Al2O3 in between the positive triboelectric layer and conducting electrode to construct an attractive flexible TENG. Based on the experimental results, the optimized three layers of graphene TENG (3L-Gr-TENG) with CTL showed a 30-fold enhancement in output power compared to its counterpart, 3L-Gr-TENG without CTL. This remarkably enhanced performance can be ascribed to the synergistic effect between the optimized graphene layers with high dielectric CTL. Moreover, the device exhibited outstanding stability after continuous operation of >2000 cycles. Additionally, the device was capable of powering 20 green LEDs and sufficient to power an electronic timer with rectifying circuits. This research provides a new insight to improve the charge density of Gr-TENGs as energy harvesters for next-generation flexible electronics.

Controlled Photoanode Properties for Large-Area Efficient and Stable Dye-Sensitized Photovoltaic Modules.

Nowadays, a dye-sensitized solar cell (DSSC) attracts attention to its development widely due to its several advantages, such as simple processes, low costs, and flexibility. In this work, we demonstrate the difference in device structures between small size and large size cells (5 cm × 5 cm, 10 cm × 10 cm and 10 cm × 15 cm). The design of the photoanode and dye-sensitized process plays important roles in affecting the cell efficiency and stability. The effects of the TiO2 electrode, using TiCl4(aq) pretreatment and post-treatment processes, are also discussed, whereas, the open-circuit voltage (Voc), short-circuit current density (Jsc), and module efficiency are successfully improved. Furthermore, the effects on module performances by some factors, such as dye solution concentration, dye soaking temperature, and electrolyte injection method are also investigated. We have demonstrated that the output power of a 5 cm × 5 cm DSSC module increases from 86.2 mW to 93.7 mW, and the module efficiency achieves an outstanding performance of 9.79%. Furthermore, enlarging the DSSC modules to two sizes (10 cm × 10 cm and 10 cm × 15 cm) and comparing the performance with different module designs (C-DSSC and S-DSSC) also provides the specific application of polymer sealing and preparing high-efficiency large-area DSSC modules.

Reducing Defects in Organic-Lead Halide Perovskite Film by Delayed Thermal Annealing Combined with KI/I2 for Efficient Perovskite Solar Cells.

This study improved quality of CH3NH3PbI3 (MAPbI3) perovskite films by delaying thermal annealing in the spin coating process and introducing KI and I2 to prepare MAPbI3 films that were low in defects for high-efficiency perovskite solar cells. The influences of delayed thermal annealing time after coating the MAPbI3 perovskite layer on the crystallized perovskite, the morphology control of MAPbI3 films, and the photoelectric conversion efficiency of solar cells were investigated. The optimal delayed thermal annealing time was found to be 60 min at room temperature. The effect of KI/I2 additives on the growth of MAPbI3 films and the corresponding optimal delayed thermal annealing time were further investigated. The addition of KI/I2 can improve perovskite crystallinity, and the conductivity and carrier mobility of MAPbI3 films. Under optimized conditions, the photoelectric conversion efficiency of MAPbI3 perovskite solar cells can reach 19.36% under standard AM1.5G solar illumination of 100 mW/cm2.

Photon-induced deactivations of multiple traps in CH3NH3PbI3 perovskite films by different photon energies.

Photon-induced trap deactivation is commonly observed in organometal halide perovskites. Trap deactivation is characterized by an obvious photoluminescence (PL) enhancement. In this work, the properties of traps in CH3NH3PbI3 perovskite films were studied based on the PL enhancement excited by lasers of different wavelengths (633 nm and 405 nm). Two types of electron traps were identified; one can be deactivated by both 633 nm and 405 nm illuminations, whereas the other one can only be deactivated by 405 nm illumination. The energy levels of both types of traps were beneath the conduction band minimum. The expressions of the PL enhancement kinetics due to the trap deactivations by lasers of different wavelengths were derived. The ratio of the constants of the radiative recombination rate and the initial capture rates for both traps was determined from the PL enhancement. The trap deactivation was a photon-related process rather than a photocarrier-related process, and the deactivation time was inversely proportional to the photon flux density.

Element Code from Pseudopotential as Efficient Descriptors for a Machine Learning Model to Explore Potential Lead-Free Halide Perovskites.

The rapid development of machine learning has proven its potential in material science. To acquire an accurate and promising result, the choice of descriptor plays an essential role in dictating the model performance. In this work, we introduce a set of novel descriptors, Element Code, which is generated from pseudopotential. Using a variational autoencoder to perform unsupervised learning, the produced Element Code is verified to contain representative information on elements. Attributed to the successful extraction of information from pseudopotential, Element Code can serve as the primary descriptor for the machine learning model. We construct a model using Element Code as the sole descriptor to predict the bandgap of a lead-free double halide perovskite, and an accuracy of 0.951 and mean absolute error of 0.266 eV are achieved. We believe our work can offer insights into selecting lead-free halide perovskites and establish a paradigm of exploring new materials.

Achieving High-Performance Perovskite Photovoltaic by Morphology Engineering of Low-Temperature Processed Zn-Doped TiO2 Electron Transport Layer.

Perovskite solar cells (PSCs) have become one of the most promising renewable energy converting devices. However, in order to reach a sufficiently high power conversion efficiency (PCE), the PSCs typically require a high-temperature sintering process to prepare mesostructured TiO2 as an efficient electron transport layer (ETL), which prohibits the PSCs from commercialization in the future. This work investigates a low-temperature synthesis of TiO2 nanocrystals and introduces a two-fluid spray coating process to produce a nanostructured ETL for the following deposition of perovskite layer. The temperature during the whole deposition process can be maintained under 150 °C. Compared to the typical planar TiO2 layer, the perovskite layer fabricated on a nanostructured TiO2 layer shows uniform compactness, preferred orientation, and high crystallinity, leading to reproducible and promising device performance. The detail mechanisms are revealed by the contact angle test, morphology characterization, grazing incident wide angle X-Ray scattering measurement, and space charge limited currents analysis. Finally, optimized device performance can be achieved through adequate Zn doping in the TiO2 layer, demonstrating an average PCE of 19.87% with champion PCE of 21.36%. The efficiency can maintain over 80% of its original value after 3000 h storage in ambient atmosphere. This study suggests a promising approach to offer high-efficiency PSCs using the low-temperature process.