Bifunctional interfacial engineering enabled efficient and stable carbon-based CsPbIBr2 perovskite solar cells.

Carbon-based inorganic CsPbIBr2 perovskite solar cells (C-IPSC) have attracted widespread attention due to their low cost and excellent thermal stability. Unfortunately, due to the soft ion crystal nature of perovskite, inherent bulk defects and energy level mismatch at the CsPbIBr2/carbon interface limit the performance of the device. In this study, we introduced aromatic benzyltrimethylammonium chloride (BTACl) as a passivation layer to passivate the surface and grain boundaries of the CsPbIBr2 film. Due to the reduction of perovskite defects and better energy level arrangement, carrier recombination is effectively suppressed and hole extraction is improved. The champion device achieves a maximum power conversion efficiency (PCE) of 11.30% with reduces hysteresis and open circuit voltage loss. In addition, unencapsulated equipment exhibits excellent stability in ambient air.

Unveil the origin of voltage oscillation for sodium-ion batteries operating at -40 °C.

Voltage oscillation at subzero in sodium-ion batteries (SIBs) has been a common but overlooked scenario, almost yet to be understood. For example, the phenomenon seriously deteriorates the performance of Na3V2(PO4)3 (NVP) cathode in PC (propylene carbonate)/EC (ethylene carbonate)-based electrolyte at -20 °C. Here, the correlation between voltage oscillation, structural evolution, and electrolytes has been revealed based on theoretical calculations, in-/ex-situ techniques, and cross-experiments. It is found that the local phase transition of the Na3V2(PO4)3 (NVP) cathode in PC/EC-based electrolyte at -20 °C should be responsible for the oscillatory phenomenon. Furthermore, the low exchange current density originating from the high desolvation energy barrier in NVP-PC/EC system also aggravates the local phase transformation, resulting in severe voltage oscillation. By introducing the diglyme solvent with lower Na-solvent binding energy, the voltage oscillation of the NVP can be eliminated effectively at subzero. As a result, the high capacity retentions of 98.3% at -20 °C and 75.3% at -40 °C are achieved. The finding provides insight into the abnormal SIBs degradation and brings the voltage oscillation behavior of rechargeable batteries into the limelight.

Small-Molecule Copper Chloride Modulating the Buried Interfaces of Perovskite Solar Cells.

In perovskite solar cells (PSCs), tin dioxide (SnO2) is a highly effective electron transport material. On the other hand, the low intrinsic conductivity of SnO2, the high trap-state density on the surface and bulk of SnO2, and inadequate interface contacts between SnO2 and perovskite significantly impact device performance. Herein, small-molecule copper(II) chloride (CuCl2) is introduced into the SnO2 dispersion, which inhibits the agglomeration of SnO2 colloids and improves the quality of the electron transport layer. Furthermore, the introduction of CuCl2 optimizes the energy-level array between the ETL and perovskite layer (PVK) and passivates the anion/cation defects in SnO2, perovskite, and their interface, realizing the systematic modulation of the photoelectronic properties of the ETLs and PVKs as well as the PVK/ETL. As a result, the CuCl2-opmized PSC exhibits an impressive power conversion efficiency of 23.71%, along with improved stability.

COVID-19 Omicron variant infection has minimal impact on maternal and neonatal outcomes: A cross-sectional cohort study.

AIM: To explore the impact of the Omicron variant on maternal and neonatal outcomes. DESIGN: Cross-sectional cohort study of women giving live birth in a single hospital in Shanghai in December 2022. METHODS: Demographic characteristics, maternal and neonatal outcomes and laboratory testing results were retrieved from medical records. Propensity score matching was used to match COVID-19-positive and -negative women. Differential analysis was used to assess associations between COVID-19 and in-hospital maternal and neonatal outcomes. RESULTS: A total of 1508 women were included, comprising 729 natural births, 741 caesarean sections and 38 forceps deliveries. After 1:1 matching, 310 clients were included for analysis with each 155 in COVID-19-positive and -negative groups. Higher maternal fever was found in all modes of delivery, and higher preterm birth and lower pH value of blood gas of the umbilical artery in the vaginal delivery subgroup (p < 0.05). Other maternal and neonatal outcomes showed no significant difference between COVID-19-positive and -negative clients.

CircPRDM5 inhibits the proliferation, migration, invasion, and glucose metabolism of gastric cancer cells by reducing GCNT4 expression in a miR-485-3p-dependent manner.

Circular RNA (circRNA) plays a key part in the pathological process of gastric cancer (GC). The study is organized to analyze the function of circPRDM5 in GC cell tumor properties. Expression levels of circPRDM5, miR-485-3p, glucosaminyl (N-acetyl) transferase 4 (GCNT4), ki67, E-cadherin, N-cadherin, and hexokinase 2 (HK2) were analyzed by quantitative real-time polymerase chain reaction (PCR), Western blotting or immunohistochemistry assay. Cell proliferation was assessed by cell colony formation assay and 5-ethynyl-2'-deoxyuridine assay. Cell migration and invasion were investigated by transwell assay. Glycolysis was evaluated by the Seahorse XF Glycolysis Stress Test Kit. Dual-luciferase reporter assay and RNA pull-down assay were performed to identify the associations among circPRDM5, miR-485-3p, and GCNT4. Xenograft mouse model assay was conducted to determine the effects of circPRDM5 on tumor formation in vivo. CircPRDM5 and GCNT4 expression were downregulated, while miR-485-3p expression was upregulated in GC tissues and cells when compared with paracancerous tissues or human gastric epithelial cells. CircPRDM5 overexpression inhibited proliferation, migration, invasion, and glucose metabolism of GC cells; however, circPRDM5 depletion had the opposite effects. CircPRDM5 repressed tumor properties of GC cells in vivo. MiR-485-3p restoration relieved circPRDM5-induced effects in GC cells. GCNT4 overexpression remitted the promoting effects of miR-485-3p mimics on GC cell malignancy. CircPRDM5 acted as a sponge for miR-485-3p, and GCNT4 was identified as a target gene of miR-485-3p. Moreover, circPRDM5 regulated GCNT4 expression by interacting with miR-485-3p.CircPRDM5 acted as a miR-485-3p sponge to inhibit GC progression by increasing GCNT4 expression, proving a potential target for GC therapy.

Poly(3-hexylthiophene)/perovskite Heterointerface by Spinodal Decomposition Enabling Efficient and Stable Perovskite Solar Cells.

The best research-cell efficiency of perovskite solar cells (PSCs) is comparable with that of mature silicon solar cells (SSCs); However, the industrial development of PSCs lags far behind SSCs. PSC is a multiphase and multicomponent system, whose consequent interfacial energy loss and carrier loss seriously affect the performance and stability of devices. Here, by using spinodal decomposition, a spontaneous solid phase segregation process, in situ introduces a poly(3-hexylthiophene)/perovskite (P3HT/PVK) heterointerface with interpenetrating structure in PSCs. The P3HT/PVK heterointerface tunes the energy alignment, thereby reducing the energy loss at the interface; The P3HT/PVK interpenetrating structure bridges a transport channel, thus decreasing the carrier loss at the interface. The simultaneous mitigation of energy and carrier losses by P3HT/PVK heterointerface enables n-i-p geometry device a power conversion efficiency of 24.53% (certified 23.94%) and excellent stability. These findings demonstrate an ingenious strategy to optimize the performance of PSCs by heterointerface via Spinodal decomposition.

Maimendong decoction regulates M2 macrophage polarization to suppress pulmonary fibrosis via PI3K/Akt/FOXO3a signalling pathway-mediated fibroblast activation.

ETHNOPHARMACOLOGICAL RELEVANCE: Mai Men Dong decoction (MMDD), a traditional Chinese medicine formula, is relevant to ethnopharmacology due to its constituents and therapeutic properties. The formula contains herbs like Ophiopogon japonicus (Thunb.) Ker Gawl., Pinellia ternata (Thunb.) Makino, Panax ginseng C.A.Mey, Glycyrrhiza uralensis Fisch, and Ziziphus jujuba Mill, Oryza sativa L., which have been used for centuries in Chinese medicine. These herbs provide a comprehensive approach to treating respiratory conditions by addressing dryness, cough, and phlegm. Ethnopharmacological studies have explored the scientific basis of these herbs and identified active compounds that contribute to their medicinal effects. The traditional usage of MMDD by different ethnic groups reflects their knowledge and experiences. Examining this formula contributes to the understanding and development of ethnopharmacology. AIM OF THE STUDY: In the case of pulmonary fibrosis (PF), treating it can be challenging due to the limited treatment options available. This study aimed to assess the potential of MMDD as a treatment for PF by targeting macrophages and the PI3K/Akt/FOXO3a signaling pathway. MATERIALS AND METHODS: In a mouse model of PF, we investigated the effects of MMDD on inflammation, fibrosis, and M2 macrophage infiltration in lung tissue. Additionally, we examined the modulation of pro-fibrotic factors and key proteins in the PI3K/Akt/FOXO3a pathway. In vitro experiments involved inducing M2-type macrophages and assessing the impact of MMDD on fibroblast activation and the PI3K/Akt/FOXO3a pathway. RESULTS: Results demonstrated that MMDD improved weight, reduced inflammation, and inhibited M2 macrophage infiltration in mouse lung tissue. It downregulated pro-fibrotic factors, such as TGF-ß1 and PDGF-RB, as well as markers of fibroblast activation. MMDD also exhibited regulatory effects on key proteins in the PI3K/Akt/FOXO3a signaling pathway. CONCLUSIONS: MMDD inhibited M2 macrophage polarization and released profibrotic factors that inhibited pulmonary fibrosis. As a result, the PI3K/Akt/FOXO3a signaling pathway is suppressed. MMDD is proving to be a successful treatment for PF. However, further research is needed to validate its effectiveness in clinical practice.

Potassium-Based Dual-Ion Batteries Operating at -60 °C Enabled By Co-Intercalation Anode Chemistry.

Battery performance at subzero is restricted by sluggish interfacial kinetics. To resolve this issue, potassium-based dual-ion batteries (K-DIBs) based on the polytriphenylamine (PTPAn) cathode with anion storage chemistry and the hydrogen titanate (HTO) anode with K+ /solvent co-intercalation mechanism are constructed. Both the PTPAn cathode and the HTO anode do not undergo the desolvation process, which can effectively accelerate the interfacial kinetics at subzero. As revealed by theoretical calculations and experimental analysis, the strong K+ /solvent binding energy in the dilute electrolyte, the charge shielding effect of the crystal water, and the uniform SEI layer with high content of the flexible organic species synergically promote HTO to undergo K+ /solvent co-intercalation behavior. The special co-intercalation mechanism and anion storage chemistry enable HTO||PTPAn K-DIBs with superior rate performance and cycle durability, maintaining a capacity retention of 94.1% after 6000 cycles at -40 °C and 91% after 1000 cycles at -60 °C. These results provide a step forward for achieving high-performance energy storage devices at low temperatures.

Synergistic Effect of 2-(Trifluoromethyl) Benzimidazole on the Stability and Performance of Perovskite Solar Cells.

The quality of the perovskite active layer directly impacts the photovoltaic performance of perovskite solar cells (PSCs). Unfortunately, perovskite films produced through solution methods often have a significant number of defects on their surface, which lead to a substantial degradation in the performance of devices. For this reason, a multifunctional additive 2-(trifluoromethyl) benzimidazole (TFMBI) is introduced into perovskite films. Based on the Lewis acid/base coordination principle, the TFMBI double site cooperatively passivates surface defects, inhibiting carrier non-radiative recombination. Simultaneously, the hydrophobic solid group (-CF3) of TFMBI covers the surface, establishing a moisture-oxygen barrier and improving the environmental stability of the devices. In consequence, the power conversion efficiency (PCE) of TFMBI-modified PSCs reached 23.16%, significantly higher than the pristine one with a PCE of 20.62%. Additionally, the unencapsulated target device retained 90.32% of its initial PCE even after being reserved in the air with a relative humidity of 20-30% for 60 days.

High-Efficiency Carbon-based CsPbI2 Br Perovskite Solar Cells from Dual Direction Thermal Diffusion Treatment with Cadmium Halides.

In recent years, carbon-based CsPbI2 Br perovskite solar cells (PSCs) have attracted more attention due to their low cost and good stability. However, the power conversion efficiency (PCE) of carbon-based CsPbI2 Br PSCs is still no more than 16%, because of the defects in CsPbI2 Br or at the interface with the electron transport layer (ETL), as well as the energy level mismatch, which lead to the loss of energy, thus limiting PCE values. Herein, a series of cadmium halides are introduced, including CdCl2 , CdBr2 and CdI2 for dual direction thermal diffusion treatment. Some Cd2+ ions thermally diffuse downward to passivate the defects inside or on the surface of SnO2 ETL. Meanwhile, the energy level structure of SnO2 ETL is adjusted, which is in favor of the transfer of electron carriers and blocking holes. On the other hand, part of Cd2+ and Cl- ions thermally diffuse upward into the CsPbI2 Br lattice to passivate crystal defects. Through dual direction thermal diffusion treatment by CdCl2 , CdI2 and CdBr2 , the performance of devices has been significantly improved, and their PCE has been increased from 13.01% of the original device to 14.47%, 14.31%, and 13.46%, respectively. According to existing reports, 14.47% is one of the highest PCE of carbon-based CsPbI2 Br PSCs with SnO2 ETLs.

Epidemiololgical and etiological analysis of two clusters of severe fever with thrombocytopenia syndrome.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease, caused by severe fever with thrombocytopenia syndrome virus (SFTSV), which is primarily transmitted via tick bites. Clusters of SFTS caused by human-to-human transmission have been reported both at home and abroad, mainly focused on the transmission or exposure modes. However, the correlation between SFTS clusters and viral genotypes has not been investigated. This study mainly reported two clusters of SFTS in Xinyang City, Henan Province, from 2022 to 2023, discussed the possible route of person-to-person transmission of SFTSV infection and analyzed the association between SFTS clusters and virus genotypes. We found that two groups of SFTSV in two clusters were clustered separately into different genotypes through viral sequence analysis of 4 confirmed patients. We also performed phylogenetic analysis, after including SFTSV sequences obtained from SFTS clusters deposited in the GenBank. Three SFTSV genotypes have been reported among cases of human-to-human transmission, suggesting that the occurrence of SFTS clusters may not be related to SFTSV genotypes. This study provided genetic evidence for revealing the chain of human-to-human transmission of SFTS clusters, indicating that contact with patients' blood is an important transmission route of SFTSV. The findings laid the foundation for preventing and controlling human-to-human transmission of SFTS.

Potential distribution of three types of ephemeral plants under climate changes.

Background: Arid and semi-arid regions account for about 40% of the world's land surface area, and are the most sensitive areas to climate change, leading to a dramatic expansion of arid regions in recent decades. Ephemeral plants are crucial herbs in this area and are very sensitive to climate change, but it is still unclear which factors can determine the distribution of ephemeral plants and how the distribution of ephemeral plants responds to future climate change across the globe. Aims: Understanding the impact of climate change on ephemeral plant distribution is crucial for sustainable biodiversity conservation. Methods: This study explored the potential distribution of three types of ephemeral plants in arid and semi-arid regions (cold desert, hot desert, and deciduous forest) on a global scale using the MaxEnt software. We used species global occurrence data and 30 environmental factors in scientific collections. Results: Our results showed that (1) the average value of the area under the receiver operating curve (AUC) of each species was higher than 0.95, indicating that the MaxEnt model's simulation accuracy for each species was good; (2) distributions of cold desert and deciduous forest species were mainly determined by soil pH and annual mean temperature; the key factor that determines the distribution of hot desert species was precipitation of the driest month; and (3) the potential distribution of ephemeral plants in the cold desert was increased under one-third of climate scenarios; in the hot desert, the potential suitable distribution for Anastatica hierochuntica was decreased in more than half of the climate scenarios, but Trigonella arabica was increased in more than half of the climate scenarios. In deciduous forests, the ephemeral plant Crocus alatavicus decreased in nearly nine-tenths of climate scenarios, and Gagea filiformis was increased in 75% of climate scenarios. Conclusions: The potential suitable distributions of ephemeral plants in the different ecosystems were closely related to their specific adaptation strategies. These results contribute to a comprehensive understanding of the potential distribution pattern of some ephemeral plants in arid and semi-arid ecosystems.

Holistically Optimizing Charge Carrier Dynamics Enables High-Performance Dye-Sensitized Solar Cells and Photodetectors.

Charge carrier events across organic electronics are ubiquitous, and the derived optimization plays a crucial effect on improving the performance of organic electronics. Herein, a two-dimensional material (Ti3C2Tx) is incorporated into titanium dioxide (TiO2) to impart the Ti3C2Tx/TiO2 hybrid film enriched hydroxy group distribution, defect-negligible surface, upshifted work function, and enhanced conductivity yet electron mobility versus the pristine TiO2 film. Therefore, intensified photon-harvesting ability, reduced charge carrier recombination, and efficient charge carrier collection are realized for dye-sensitized solar cells (DSSCs) based on the Ti3C2Tx/TiO2 hybrid photoanode relative to control ones. Consequently, the modified DSSCs based on Z907 deliver superior efficiencies of 10.39 and 29.68% under 100 mW/cm2 illumination and ∼1.9 mW/cm2 dim light, respectively, being the highest values of Z907-based DSSCs. However, control devices only obtain lower efficiencies of 8.06 and 23.91% when undergoing the abovementioned illumination. On the other hand, the self-powered homologous photodetectors with the hybrid film as an electron-transporting layer present enhanced detectivity (1.69 × 1011 Jones) and a shortened responsivity of 0.26 s versus that of control ones (1.39 × 1011 Jones and 0.35 s). Our work implies that the Ti3C2Tx/TiO2 hybrid film features high potential for improving the performance of organic electronics for its effect of holistically optimizing charge carrier dynamics.

High-efficiency and ultraviolet stable carbon-based CsPbIBr2 solar cells from single crystal three-dimensional anatase titanium dioxide nanoarrays with ultraviolet light shielding function.

TiO2 is commonly used to prepare electron transport layers (ETLs) in perovskite solar cells (PSCs). However, conventional TiO2 ETLs suffer from low electron mobility and charge recombination. Here, we report the direct growth of TiO2 ETLs on fluorine doped conductive (FTO) glasses with titanium tetrafluoride (TiF4) as the reactant by hydrothermal method. The TiO2 ETLs have pure anatase phase, single crystal structure and three-dimensional (3D) nanoarrays morphology. This 3D-TiO2 ETLs mainly consist of thermodynamically stable surfaces {101} and more reactive surfaces {001}. Compared with the conventional TiO2 ETLs, the 3D-TiO2 ETLs can effectively optimize energy level matching and charge transfer dynamics. The special morphology of 3D-TiO2 ETLs can well assist to form high quality CsPbIBr2 with larger crystal grains. The champion CsPbIBr2 PSC with 3D-TiO2 ETL achieves an efficiency as high as 10.65%, which is equal to the one with hole-transport and Au electrode structure (10.79%) and much higher than the pristine one (7.16%) with the conventional TiO2 ETL. Furthermore, the 3D-TiO2 ETLs show ultraviolet (UV) shielding function, which can effectively overcome the UV instability defect of conventional TiO2 ETLs and obviously enhance UV stability of CsPbIBr2 and the corresponding PSCs. Therefore, the 3D-TiO2 ETLs can be good candidates for preparing high-efficiency and UV stable carbon-based CsPbIBr2 PSCs.

Bulky ammonium iodide and in-situ formed 2D Ruddlesden-Popper layer enhances the stability and efficiency of perovskite solar cells.

The practical applications of perovskite solar cells (PSCs) are limited by the further improvement of their stability and performance. Interface engineering is a promising strategy to solve these pain points. Herein, we design (R)-(-)-1-cyclohexylethylamine iodide (R-CEAI), composed of positively charged hydrophobic R-CEA+ and negatively charged I-, to post-treat the interface of 3D mixed-cation/halide perovskite with assist one of isopropyl alcohol (IPA). R-CEAI treatment not only passivates the defects at surface and grain boundaries of perovskite, but also in-situ grows quasi 2D Ruddlesden-Popper perovskite at the interface between 3D perovskite and hole transport layer, which reduces trap density of states, tunes energy level and alleviates lattice distortion. As a result, R-CEAI treated 2D/3D PSCs yield a champion PCE of 22.52%, with an improved open-circuit voltage of 1.195 V and retain 84.34% of their initial efficiency in long-term stability test, while the pristine device provides a PCE of 19.43% with only 54.30% retention.

n-type absorber by Cd2+ doping achieves high-performance carbon-based CsPbIBr2 perovskite solar cells.

High efficiency and stability have long been the key issues faced by perovskite solar cells (PSCs). It is found that the CsPbIBr2 all-inorganic perovskite has a suitable band gap and satisfactory stability, so it has attracted much attention. However, the many defects in the CsPbIBr2 film are one of the main problems hindering the improvement of power conversion efficiency (PCE) of the CsPbIBr2 PSCs. The substitution of trace impurities is undoubtedly a simple, cost-effective and efficient strategy. In this work, an appropriate amount of Cd2+ (1.0% mol of Pb2+) is added into the CsPbIBr2 precursor solution to fabricate high quality CsPbIBr2 film with improved crystallinity, reduced trap density, suppressed photo-generated carrier recombination, displayed n-type doping and optimized energy level alignment. The corresponding carbon-based all-inorganic Cd2+-doped CsPbIBr2 PSCs achieve a maximum PCE of 10.63% with a high open circuit voltage (VOC) of 1.324 V, which are much higher than those of the control one with a PCE of 8.48% and an VOC of 1.235 V. The unencapsulated device can still retain more than 92% of the initial PCE when stored at ambient atmosphere (25 °C, relative humidity about 30%) for 40 days.

Enhancing efficiency of perovskite solar cells from surface passivation of Co2+ doped CuGaO2 nanocrystals.

Before completely applying inorganic materials as hole transport materials (HTM) for perovskite solar cells (PSCs), modifying devices with inorganic oxides that have the potential as inorganic hole transporters is an effective way to improve device performance and stability. Co2+ doped CuGaO2 nanocrystals (Co-CuGaO2 NCs) with sizes about 20 nm are synthesized by hydrothermal method and used for surface passivation at the interface of perovskite (PVK)/2,2',7,7'-Tetrakis[N,N-di (4-methoxyphenyl) amino]-9,9'-spirobifluorene (spiroOMeTAD). Co-CuGaO2 NCs have a larger bandgap with lower valance band compared with spiroOMeTAD, which is more beneficial to the conduction of holes and the blocking of electrons. Furthermore, the Co-CuGaO2 has a lower valance band energy compared with the original CuGaO2, which reduces the energy gap between Co-CuGaO2 and PVK. Co-CuGaO2 NCs fully cover the upper surface of PVK, which helps prevent direct contact between PVK and oxygen and moisture. The Co-CuGaO2 NCs surface passivation also gives better hole transport as revealed by the ultraviolet photoelectron spectroscopy (UPS), steady-state photoluminescence (PL), and time-resolved photoluminescence (TRPL) data. When the concentration of Co-CuGaO2 NCs solution is set to 7.5 mg mL-1, the device exhibits a best PCE of 20.39% and maintains 84.34% of the initial power conversion efficiency (PCE) after stored 30 days under air atmosphere with 15 ±â€¯5% humidity.

Surface Reconstruction and In Situ Formation of 2D Layer for Efficient and Stable 2D/3D Perovskite Solar Cells.

The 2D/3D composite structure possesses both the excellent stability of 2D perovskite and the excellent performance of 3D perovskite, which recently have attracted special attention. Different from the popular isopropanol, a novel additive solvent-polypropylene glycol bis (2-aminopropyl ether) (A-PPG) is introduced here to dissolve excess PbI2 and perovskite, and then reconstruct and in situ form the quasi-2D perovskite layer on 3D perovskite bulk. The lone electron pairs of the ether-oxygen and amino in A-PPG can form coordination bonds with Pb2+ . The introduction of A-PPG tunes the energy array of functional layers, passivates defects, and mitigates carrier nonradiative recombination. Consequently, the 2D/3D perovskite device exhibits a championship efficiency of 22.24% with a distinguished open-circuit voltage of 1.21 V (the thermodynamic limit of 1.30 V). Moreover, the 2D/3D device still maintains 90% of the original efficiency in the ambient atmosphere with a relative humidity of 30 ± 10% after 50 days.

Alkali Metal Fluoride-Modified Tin Oxide for n-i-p Planar Perovskite Solar Cells.

The practical applications of perovskite solar cells (PSCs) are limited by further improvement of their stability and performance. Additive engineering and interface engineering are promising medicine to cure this stubborn disease. Herein, an alkali metal fluoride as an additive is introduced into the tin oxide (SnO2) electron transport layer (ETL). The formation of coordination bonds of F- ions with the oxygen vacancy of Sn4+ ions decreases the trap-state density and improves the electron mobility; the hydrogen bond interaction between the F ion and amine group (FA+) of perovskite inhibits the diffusion of organic cations and promotes perovskite (PVK) stability. Meanwhile, the alkali metal ions (K+, Rb+, and Cs+) permeated into PVK fill the organic cation vacancies and ameliorate the crystal quality of PVK films. Consequently, a SnO2-based planar PSC exhibits a power conversion efficiency (PCE) of 20.24%, while the PSC modified by CsF achieves a PCE of 22.51%, accompanied by effective enhancement of stability and negligible hysteresis. The research results provide a typical example for low-cost and multifunctional additives in high-performance PSCs.

Marked Passivation Effect of Naphthalene-1,8-Dicarboximides in High-Performance Perovskite Solar Cells.

As game-changers in the photovoltaic community, perovskite solar cells are making unprecedented progress while still facing grand challenges such as improving lifetime without impairing efficiency. Herein, two structurally alike polyaromatic molecules based on naphthalene-1,8-dicarboximide (NMI) and perylene-3,4-dicarboximide (PMI) with different molecular dipoles are applied to tackle this issue. Contrasting the electronically pull-pull cyanide-substituted PMI (9CN-PMI) with only Lewis-base groups, the push-pull 4-hydroxybiphenyl-substituted NMI (4OH-NMI) with both protonic and Lewis-base groups can provide better chemical passivation for both shallow- and deep-level defects. Moreover, combined theoretical and experimental studies show that the 4OH-NMI can bind more firmly with perovskite and the polyaromatic backbones create benign midgap states in the excited perovskite to suppress the damage by superoxide anions (energetic passivation). The polar and protonic nature of 4OH-NMI facilitates band alignment and regulates the viscosity of the precursor solution for thicker perovskite films with better morphology. Consequently, the 4OH-NMI-passivated perovskite films exhibit reduced grain boundaries and nearly three-times lower defect density, boosting the device efficiency to 23.7%. A more effective design of the passivator for perovskites with multi-passivation mechanisms is provided in this study.