Improving the Efficiency and Stability of Perovskite Solar Cells by Refining the Perovskite-Electron Transport Layer Interface and Shielding the Absorber from UV Effects.

This study aims to enhance the performance of perovskite solar cells (PSCs) by optimizing the interface between the perovskite and electron transport layers (ETLs). Additionally, we plan to protect the absorber layer from ultraviolet (UV) degradation using a ternary oxide system comprising SnO2, strontium stannate (SrSnO3), and strontium oxide (SrO). In this structure, the SnO2 layer functions as an electron transport layer, SrSnO3 acts as a layer for UV filtration, and SrO is employed to passivate the interface. SrSnO3 is characterized by its chemical stability, electrical conductivity, extensive wide band gap energy, and efficient absorption of UV radiation, all of which significantly enhance the photostability of PSCs against UV radiation. Furthermore, incorporating SrSnO3 into the ETL improves its electronic properties, potentially raising the energy level and improving alignment, thereby enhancing the electron transfer from the perovskite layer to the external circuit. Integrating SrO at the interface between the ETL and perovskite layer reduces interface defects, thereby reducing charge recombination and improving electron transfer. This improvement results in higher solar cell efficiency, reduced hysteresis, and extended device longevity. The benefits of this method are evident in the observed improvements: a noticeable increase in open-circuit voltage (Voc) from 1.12 to 1.16 V, an enhancement in the fill factor from 79.4 to 82.66%, a rise in the short-circuit current density (Jsc) from 24.5 to 24.9 mA/cm2 and notably, a marked improvement in the power conversion efficiency (PCE) of PSCs, from 21.79 to 24.06%. Notably, the treated PSCs showed only a slight decline in PCE, reducing from 24.15 to 22.50% over nearly 2000 h. In contrast, untreated SnO2 perovskite devices experienced a greater decline, with efficiency decreasing from 21.79 to 17.83% in just 580 h.

Shape Reconstruction of Extensible Continuum Manipulator Based on Soft Sensors.

Continuum manipulators can improve spatial adaptability and operational flexibility in constrained environments by endowing them with contraction and extension capabilities. There are currently desired requirements to quantify the shape of an extensible continuum manipulator for strengthening its obstacle avoidance capability and end-effector position accuracy. To address these issues, this study proposes a methodology of using silicone rubber strain sensors (SRSS) to estimate the shape of an extensible continuum manipulator. The way is to measure the strain at specific locations on the deformable body of the manipulator, and then reconstruct the shape by integrating the information from all sensors. The slender sensors are fabricated by a rolling process that transforms planar silicone rubber sensors into cylindrical structures. The proprioceptive model relationship between the strain of the sensor and the deformation of the manipulator is established with considering the phenomenon of torsion of the manipulator caused by compression. The physically extensible continuum manipulator equipped with three driving tendons and nine SRSS was designed. Comprehensive evaluations of various motion trajectories indicate that this method can accurately reconstruct the shape of the manipulator, especially under end-effector loads. The experimental results demonstrate that the mean (maximum) absolute position error of the endpoint is 1.61% (3.45%) of the manipulator length.

Clinical study reveals the efficacy of sirolimus in treating primary immune thrombocytopenia: findings from a single-center study.

Immune thrombocytopenia (ITP) is an autoimmune disease that arises because of self-destruction of circulating platelets. The mechanism remains complicated and lacks a standard clinical treatment. Current first-line and second-line medications for ITP have shown limited effectiveness, necessitating the exploration of new therapeutic options. Sirolimus is a mammalian target of rapamycin (mTOR) inhibitor that has been demonstrated to inhibit lymphocyte activity, indicating potential for SRL in the treatment of ITP. This study aimed to evaluate the clinical efficacy of sirolimus as a second-line drug in patients with ITP. The starting dose of sirolimus for adults ranged from 2 to 4 mg/day, with a maintenance dose of 1 to 2 mg/day. For children, the starting dose was 1-2 mg/day, with a maintenance dose of 0.5-1 mg/day. The dosage could be adjusted if needed to maintain a specific blood concentration of sirolimus, typically between 5 and 15 ng/ml, throughout the treatment period. After 3 months, the overall response rate was 60% (12/20), with 30% of patients (6/20) achieving a complete response (CR) and 30% (6/20) achieving a partial response (PR). The CR rate at 6 months remained consistent with the 3-month assessment. No major adverse events were reported, indicating that sirolimus was well tolerated and safe. Analysis of peripheral blood Treg cell percentages in both the control and ITP showed no significant difference before treatment. The percentage of Treg cells increased after treatment with sirolimus, suggesting that sirolimus increases Treg cells. These findings suggest that sirolimus serves as an effective second-line treatment option for ITP, demonstrating favorable clinical efficacy.

Novel near-infrared BODIPY-cyclodextrin complexes for photodynamic therapy.

To meet the requirements of diagnosis and treatment, photodynamic therapy (PDT) is a promising cancer treatment with less side-effect. A series of novel BODIPY complexes (BODIPY-CDs) served as PDT agents were first reported to enhance the biocompatibility and water solubility of BODIPY matrix through the click reaction of alkynyl-containing BODIPY and azide-modified cyclodextrin (CD). BODIPY-CDs possessed superior water solubility due to the introduction of CD and their fluorescence emission apparently redshifted (>90 nm) on account of triazole units as the linkers compared to alkynyl-containing BODIPY. Moreover, all the BODIPY-CDs were no cytotoxicity toward NIH 3T3 in different drug concentrations from 12.5 to 200 µg/mL, and had a certain inhibitory effect on tumor HeLa cells. Particularly, BODIPY-ß-CD exhibited high reactive oxygen species generation and excellent photodynamic therapy activity against HeLa cells compared to other complexes. The cell viability of BODIPY-ß-CD was dramatically reduced up to 20% in the concentration of 100 µg/mL upon 808 nm laser irradiation. This architecture might provide a new opportunity to develop valuable photodynamic therapy agents for tumor cells.

Novel nanoparticles prepared from isothiocyanate derivatives for phototherapy of tumor.

Phototherapy is a new method to treat tumor, including photodynamic therapy (PDT) and photothermal therapy (PTT). However, the GSH in tumor cells could deplete ROS produced by photosensitizers, resulting in inadequate PDT. Isothiocyanate not only is a new type of anti-tumor drug, but also may combine with GSH, increasing the content of intracellular ROS and improving PDT effect. Here we synthesized a kind of water-soluble nanoparticles (BN NPs) parceling BODIPY-I-35 up with mPEG-ITC and lecithin. mPEG-ITC can react with GSH in tumor cells to reduce the consumption of ROS. BN NPs can be used as vectors to deliver drugs to tumor sites. Under 808 nm laser irradiation, BN NPs solution increased 13 °C within 10 min, indicating that BN NPs had superb photothermal performance. In vitro experiments, low dose BN NPs showed satisfactory PDT and PTT effects, and the cell viability of MCF-7 cell was only 13%. In vivo, BN NPs with excellent biocompatibility showed favorable phototherapy effect and tumor was effectively inhibited. Fluorescence imaging could present the long retention effect of BN NPs in tumor locations. In conclusion, the BN NPs showed the effect of enhancing phototherapy and provided a remarkable application prospect in the phototherapy of tumor cells.

Anti-MOG Antibody-Associated Unilateral Cortical Encephalitis with Bilateral Meningeal Involvement: A Case Report.

A 27-year-old Han Chinese woman presented with fever, headache, lethargy, and difficulty in expression. Magnetic resonance imaging (MRI) detected extensive hyperintensity of the left-sided frontoparietal, temporal, occipital, and insular cortices via fluid-attenuated inversion recovery (FLAIR) imaging. Post-contrast MRI revealed linear enhancement in the frontoparietal, temporal, and occipital sulci bilaterally. The detection of anti-myelin oligodendrocyte glycoprotein (MOG) was positive in the cerebrospinal fluid (CSF) and serum. The patient was diagnosed with anti-MOG antibody-associated unilateral cortical encephalitis with bilateral meningeal involvement. The patient received low doses of intravenous dexamethasone followed by oral prednisone, which was tapered until withdrawal. The treatment significantly improved the patient's symptoms. A one-month follow-up showed that the patient gradually resumed her normal lifestyle. No further relapse was recorded after a one-year follow-up. MRI performed almost a year after the initial symptom onset showed that the FLAIR signal had decreased in the left insular lobe, and the abnormal cortical signal of the FLAIR in the original left frontotemporal occipital lobe had disappeared. Thus, we report a rare case of anti-MOG antibody encephalitis (unilateral cortical encephalitis with bilateral meningeal involvement) in an adult patient. This study provides a reference for the clinical diagnosis and treatment of MOG antibody-associated unilateral cortical encephalitis.

Reduced VOC Deficit of Mixed Lead-Tin Perovskite Solar Cells via Strain-Releasing and Synergistic Passivation Additives.

The power conversion efficiency (PCE) of tin-lead perovskite solar cells (PSCs) is normally lower than that of Pb cells, mainly due to greater open circuit voltage (VOC ) losses. Herein, the additive 2,6-diaminopyridine (TNPD) is designed to anchor on the surface of the perovskite precursor colloid as nucleating agent to modulate the growth of Pb-Sn perovskites. It is observed that the TNPD not only effectively induces crystal growth during the nucleation stage, remaining on the crystal surface and ultimately passivating the resulting perovskite films, but also releases the micro-strain generated during the film growth. Furthermore, TNPD could lower the defect density (Sn4+ amount) by screening the perovskite against oxygen and by synergistically bonding with undercoordinated Sn/Pb on the surface. Finally, a high VOC of 0.85 V is obtained, corresponding to a voltage deficit of 0.41 V using a perovskite absorber with a bandgap of 1.26 eV, and a high PCE (20.35%) reported so far for Pb-Sn PSCs. Moreover, the stability of the TNPD-incorporated device is significantly improved, and the PCE maintains 50% of the initial value after about 1000 h storage in glovebox without encapsulated, in comparison to that of the control device (about 700 h, maintaining 30% of the initial value).

Area-Scalable Zn2SnO4 Electron Transport Layer for Highly Efficient and Stable Perovskite Solar Modules.

The development of a scalable chemical bath deposition (CBD) process facilitates the realization of electron-transporting layers (ETLs) for large-area perovskite solar modules (PSMs). Herein, a method to prepare a uniform and scalable thick Zn2SnO4 ETL by CBD, which yielded high-performance PSMs, is reported. This Zn2SnO4 ETL exhibits excellent electrical properties and enhanced optical transmittance in the visible region. Moreover, the Zn2SnO4 ETL influences the perovskite layer formation, yielding enhanced crystallinity, increased grain size, and a smoother surface, thus facilitating electron extraction and collection from the perovskite to the ETL. Zn2SnO4 thereby yields PSMs with a remarkable photovoltaic performance, low hysteresis index, and high device reproducibility. The champion PSM exhibited a power conversion efficiency (PCE) of 22.59%, being among the highest values published so far. In addition, the CBD Zn2SnO4-based PSMs exhibit high stability, retaining more than 88% of initial efficiency over 1000 h under continuous illumination. This demonstrates that CBD Zn2SnO4 is an appropriate ETL for high-efficiency PSMs and a viable new process for their industrialization.

Ultraviolet Filtration Passivator for Stable High-Efficiency Perovskite Solar Cells.

Although the published values of power conversion efficiency (PCE) have increased continuously in recent years for perovskite solar cells (PSCs), improvements in the stability and performance of PSCs with conventional TiO2 or SnO2 electron transport layers (ETLs) remain limited by the presence of nonideal interface defects and low ultraviolet (UV) absorption. In this study, 2-hydroxy-4-methoxy-5-sulfonate-benzophenone (SBP), an inexpensive water-soluble sunscreen raw material, was incorporated into the SnO2 ETL as a UV filter. It was found that the exposure of perovskite to UV light was significantly reduced, and, more importantly, the carbonyl and sulfonic acid groups in the SBP influenced both the perovskite crystallization process and the passivation of defects in the ETL/perovskite film interface. As a result, the PCE of SBP-based devices was increased to 22.54% from 20.78% of the control sample, with a concomitant decrease in the hysteresis. Moreover, the efficiency of champion devices with SBP decreased by less than 5% after 200 h of continuous UV (1.63 mW/cm2, 285 nm) irradiation, while the control group dropped to below 75% of the initial value, thus showing significantly improved stability.

Role of the Backbone when Optimizing Functional Groups─A Theoretical Study Based on an Improved Inverse-Design Approach.

We present an improved inverse-design approach for automatically identifying molecular (or other) systems with optimal values for prechosen properties. The new approach uses SMILES (simplified molecular input line entry system) to describe molecular structures efficiently, a genetic algorithm to optimize the molecules automatically, and the DFTB+ (self-consistent charge density functional tight-binding) method to calculate electronic properties. Thereby, almost every class of materials─even macromolecules or monomers─can be studied easily. Without crossover operators but with only mutation operators, the genetic algorithm is more adaptive to SMILES while keeping its efficiency. DFTB+ is more accurate than the DFTB method used in our previous inverse-design approach for the study of excited states and charge transfer processes. The improved approach is applied to optimize benzene, pyridine, pyridazine, pyrimidine, and pyrazine derivatives for seven electronic properties, which all are highly relevant and important for the performance of molecules in solar cells. We found that for some electronic properties, the precise composition and structure of the backbone have remarkable impacts on the value of the electronic properties and/or on the set of functional groups that leads to the best performance. On the contrary, for other properties, these effects are less pronounced. The reasonable optimal functional groups and/or substitution patterns are reported.

The photodynamic/photothermal synergistic therapeutic effect of BODIPY-I-35 liposomes with urea.

Photodynamic therapy (PDT) has a successful track record in cancer. . Urea is a naturally occurring metabolite in the human body. Some studies have shown that it can inhibit the proliferation of tumor cells and cause oxidative stress. In order to explore the application of urea in enhancing the PDT effect, we synthesized a new photosensitizer (BODIPY-I-35) with good phototherapeutic effect and encapsulated it in liposomes. Compared with free BODIPY-I-35, water-soluble nanoliposomes (LipoBOD) produced a huge redshift (> 122 nm) of fluorescence emission in solution. When LipoBOD was irradiated with 808 nm laser (1 W/cm2) for 10 min, the temperature contrast increased by 20 °C, which was 4 times higher than free BODIPY-I-35. Confocal microscopy showed appreciable accumulation of LipoBOD in HeLa cells. In addition, when LipoBOD was incubated with urea in HeLa cells, we found that urea not only obviously enhanced the production of ROS, but also increased the apoptosis of HeLa cells. The synergistic effect of LipoBOD (20 µg/mL, at BODIPY-I-35-eq) with urea (250 mM) showed significantly higher phototoxicity than LipoBOD alone. Low dose can reduce the cell viability to 10%. Therefore, we have obtained an effective method of using urea to enhance the PDT effect.

The tumor phototherapeutic application of nanoparticles constructed by the relationship between PTT/PDT efficiency and 2,6- and 3,5-substituted BODIPY derivatives.

BODIPY dyes have recently been used for photothermal and photodynamic therapy of tumors. However, complex multi-material systems, multiple excitation wavelengths and the unclear relationship between BODIPY structures and their PTT/PDT efficiency are still major issues. In our study, nine novel BODIPY near-infrared dyes were designed and successfully synthesized and then, the relationships between BODIPY structures and their PTT/PDT efficiency were investigated in detail. The results showed that modifications at position 3,5 of the BODIPY core with conjugated structures have better effects on photothermal and photodynamic efficiency than the modifications at position 2,6 with halogen atoms. Density functional theory (DFT) calculations showed that this is mainly due to the extension of the conjugated chain and the photoinduced electron transfer (PET) effect. By encapsulating BDPX-M with amphiphilic DSPE-PEG2000-RGD and lecithin, the obtained NPs not only show good water solubility and biological stability, but also could act as superior agents for photothermal and photodynamic synergistic therapy of tumors. Finally, we obtained BODIPY NPs that exhibited excellent photothermal and photodynamic effects at the same time under single irradiation with an 808 nm laser (photothermal conversion efficiency: 42.76%, A/A0: ∼0.05). In conclusion, this work provides a direction to design and construct phototherapeutic nanoparticles based on BODIPY dyes for tumor treatment.

A Porphyrin-Involved Benzene-1,3,5-Tricarboxamide Dendrimer (Por-BTA) as a Multifunctional Interface Material for Efficient and Stable Perovskite Solar Cells.

Surface defects of perovskite films are the major sources of nonradiative recombination which limit the efficiency and stability of perovskite solar cells. Surface passivation represents one of the most efficient strategies to solve this problem. Herein, for the first time we designed a porphyrin-involved benzene-1,3,5-tricarboxamide dendrimer (Por-BTA) as a multifunctional interface material between the interface of the perovskite and the hole-transporting layer (spiro-OMeTAD) for the surface passivation of perovskite films. The results suggested that Por-BTA not only efficiently passivated the perovskite surface defects via the coordination of the exposed Pb2+ with the carbonyl unit and basic sites of pyrrole units in Por-BTA but also improved the interface contact and the charge transfer between the perovskite and spiro-OMeTAD ascribed to the strong intermolecular π-π stacking of Por-BTA. It was shown that the PSC devices with the Por-BTA treatment exhibited improved power conversion efficiency with the champion of 22.30% achieved (21.30% for the control devices), which is mainly attributed to the increased short-circuit current density and fill factor. Interestingly, the stability of moisture for the Por-BTA-treated device was also enhanced compared to those without the Por-BTA treatment. This work presents a promising direction toward the design of multifunctional organic molecules as the interface materials to improve the cell performance of PSCs.

Construction of Pyridine-Based Chiral Ionic Covalent Organic Frameworks as a Heterogeneous Catalyst for Promoting Asymmetric Henry Reactions.

The difficulties in the separation of products from the reaction mixture and the recovery of the organic cationic ionic liquids (OCILs) catalysts still need to be addressed. Post modification of the pyridine unit in the covalent organic framework (COF) via the formation of pyridinium salts with the chiral bromoacetate led to the chiral ionic COF with OCIL "immobilized", which was utilized as a heterogeneous catalyst for asymmetric Henry reactions with high yield and excellent stereoselectivity.

Multi-functional Nanodrug Based on a Three-dimensional Framework for Targeted Photo-chemo Synergetic Cancer Therapy.

Targeted synergistic therapy has broad prospects in tumor treatments. Here, a multi-functional nanodrug GDYO-CDDP/DOX@DSPE-PEG-MTX (GCDM) based on three traditional anticancer drugs (doxorubicin (DOX), cisplatin (CDDP) and methotrexate (MTX)) modified graphdiyne oxide (GDYO) is described, for diagnosis and targeted cancer photo-chemo synergetic therapy. In this system, for the first time, these three traditional anti-cancer drugs have played new roles and can reduce multidrug resistance through synergistic anti-tumor effects. Cisplatin can be hybridized with GDYO to form a multifunctional and well-dispersed three-dimensional framework, which can not only be used as nano-drug carriers to achieve high drug loading rates (40.3%), but also exhibit excellent photothermal conversion efficiency (47%) and good photodynamic effects under NIR irradiation. Doxorubicin (DOX) is loaded onto GDYO-CDDP through π-π stacking, which is used as an anticancer drug and as a fluorescent probe for nanodrug detection. Methotrexate (MTX) can be applied in tumor targeting and play a role in synergistic chemotherapy with DOX and CDDP. The synthesized multi-functional nanodrug GCDM has good biocompatibility, active targeting, long-term retention, sustained drug release, excellent fluorescence imaging capabilities, and remarkable photo-chemo synergistic therapeutic effects.

Blue nanocomposites coated with an ionic liquid polymer for electrophoretic displays.

Electrophoretic display (EPD) is a type of flexible display which has attracted wide attention. In this work, blue nanosized crystals of cobalt aluminum oxide (CoAl2O4) were precipitated on silica nanoparticles, and then the nanocomposites were coated with an ionic liquid polymer (PIL) to give blue electrophoretic particles. The blue nanocomposites (SCAs) formed possess an excellent spherical structure, and the average diameter is about 188 nm. The porous silica matrix presents a relative light density, and the blue CoAl2O4 pigment offers excellent color. The outside ionic liquid polymer supplies the PIL/SCAs with a light density of 1.7915 g cm-3, excellent hydrophobicity and dispersion stability in the electrophoretic liquid. The fabricated single-particle EPD prototypes show a response time of 165 ms in the EPD cell with a 0.2 mm thickness, which is much faster than the commercial EPDs, and this is probably because of the unique composite structure.

Effects of interfacial adsorption configurations on dye-sensitized solar cell performance at the stoichiometric and defective TiO2 anatase (101) surfaces: a theoretical investigation.

Interfacial adsorption configuration plays a crucial role in influencing the photovoltaic performance of dye-sensitized solar cells (DSSCs), and thus, theoretical investigations are needed to further understand the impacts of different absorption configurations on stoichiometric and defective TiO2(101) surfaces on the short-circuit photocurrent density (JSC) and open-circuit voltage (VOC) of DSSCs. Herein, calculations of isolated dyes and dye/TiO2 systems were performed on the donor-π bridge-acceptor (D-π-A) type porphyrin sensitizers bearing different donor moieties and an α-cyanoacrylic acid anchoring group (T1-3), using DFT and TD-DFT methods. And, for the first time, comparative analysis of interfacial electron transfer (IET) and density of states (DOS) were carried out on dye/TiO2 systems with stoichiometric and defective surfaces to provide further insight into the electronic factors influencing the efficiency of DSSCs, which can well explain the experimental variation trends of JSC and VOC values. It turned out that attachment via the carboxyl and cynao groups in a tridentate binding mode can result in more efficient IET rates and an upshifted conduction band in comparison with those of the bidentate attachment. More interestingly, we found that the adsorption configuration on defective surfaces containing an O2c vacancy induced more upshifted CBM and relatively fast IET, especially for the bonding mode through two O atoms of the carboxyl group.

Stable and High-Efficiency Methylammonium-Free Perovskite Solar Cells.

Organic-inorganic metal halide perovskite solar cells (PSCs) have achieved certified power conversion efficiency (PCE) of 25.2% with complex compositional and bandgap engineering. However, the thermal instability of methylammonium (MA) cation can cause the degradation of the perovskite film, remaining a risk for the long-term stability of the devices. Herein, a unique method is demonstrated to fabricate highly phase-stable perovskite film without MA by introducing cesium chloride (CsCl) in the double cation (Cs, formamidinium) perovskite precursor. Moreover, due to the suboptimal bandgap of bromide (Br- ), the amount of Br- is regulated, leading to high power conversion efficiency. As a result, MA-free perovskite solar cells achieve remarkable long-term stability and a PCE of 20.50%, which is one of the best results for MA-free PSCs. Moreover, the unencapsulated device retains about 80% of the original efficiencies after a 1000 h aging study. These results provide a feasible approach to enhance solar cell stability and performance simultaneously, paving the way for commercializing PSCs.

A Corrole-Based Covalent Organic Framework Featuring Desymmetrized Topology.

Herein, for the first time, we present the successful synthesis of a novel two-dimensional corrole-based covalent organic framework (COF) by reacting the unusual approximately T-shaped 5,10,15-tris(p-aminophenyl)corrole H3 TPAPC with terephthalaldehyde, which adopts desymmetrized hcb topology and consists of a staggered AB stacking structure with elliptical pores. The resultant corrole-based COF, TPAPC-COF, exhibits high crystallinity and excellent chemical stability. The combination of extended π-conjugated backbone and interlayer noncovalent π-π interactions endows TPAPC-COF with excellent absorption capability in the entire visible-light and even near-infrared regions. Moreover, this work suggests the promise of TPAPC-COF as a new class of photoactive material for efficient singlet-oxygen generation with potential photodynamic therapy application as demonstrated by in vitro anticancer studies.