Pd(II)/Pd(IV) redox shuttle to suppress vacancy defects at grain boundaries for efficient kesterite solar cells

Charge loss at grain boundaries of kesterite Cu2ZnSn(S, Se)4 polycrystalline absorbers is an important cause limiting the performance of this emerging thin-film solar cell. Herein, we report a Pd element assisted reaction strategy to suppress atomic vacancy defects in GB regions. The Pd, on one hand in the form of PdSex compounds, can heterogeneously cover the GBs of the absorber film, suppressing Sn and Se volatilization loss and the formation of their vacancy defects (i.e. VSn and VSe), and on the other hand, in the form of Pd(II)/Pd(IV) redox shuttle, can assist the capture and exchange of Se atoms, thus contributing to eliminating the already-existing VSe defects within GBs. These collective effects have effectively reduced charge recombination loss and enhanced p-type characteristics of the kesterite absorber. As a result, high-performance kesterite solar cells with a total-area efficiency of 14.5% (certified at 14.3%) have been achieved.

A Ni-O-Ag photothermal catalyst enables 103-m2 artificial photosynthesis with >17% solar-to-chemical energy conversion efficiency

The scalable artificial photosynthesis composed of photovoltaic electrolysis and photothermal catalysis is limited by inefficient photothermal CO2 hydrogenation under weak sunlight irradiation. Herein, NiO nanosheets supported with Ag single atoms [two-dimensional (2D) Ni1Ag0.02O1] are synthesized for photothermal CO2 hydrogenation to achieve 1065 mmol g-1 hour-1 of CO production rate under 1-sun irradiation. This performance is attributed to the coupling effect of Ag-O-Ni sites to enhance the hydrogenation of CO2 and weaken the CO adsorption, resulting in 1434 mmol g-1 hour-1 of CO yield at 300°C. Furthermore, we integrate the 2D Ni1Ag0.02O1-supported photothermal reverse water-gas shift reaction with commercial photovoltaic electrolytic water splitting to construct a 103-m2 scale artificial photosynthesis system (CO2 + H2O → CO + H2 + O2), which achieves more than 22 m3/day of green syngas with an adjustable H2/CO ratio (0.4-3) and a photochemical energy conversion efficiency of >17%. This research charts a promising course for designing practical, natural sunlight-driven artificial photosynthesis systems.

[Immune reconstitution and influencing factors in HIV infected men who have sex with men with access to antiviral therapy in Guangxi Zhuang Autonomous Region from 2005 to 2021]

Objective: To analyze immune reconstitution and influencing factors in HIV infected men who have sex with men (MSM) with access to antiviral therapy (ART) in Guangxi Zhuang Autonomous Region (Guangxi) during 2005-2021. Methods: The data were collected from Chinese Disease Prevention and Control Information System. The study subjects were HIV infected MSM with access to the initial ART for ≥24 weeks in Guangxi from 2005 to 2021 and HIV RNA lower than the detection limit within 24 months. The proportion of infected MSM who had immune reconstitution after ART was calculated. Cox proportional hazard regression model was used to analyze the influencing factors of immune reconstitution. Software SPSS 24.0 was used for statistical analysis. Results: A total of 3 200 HIV infected MSM were enrolled, in whom 15.56 % (498/3 200) had no immune reconstitution, 14.78% (473/3 200) had moderate immune reconstitution, and the rate of complete immune reconstitution was 69.66% (2 229/3 200). The M (Q1, Q3) of ART time for immune reconstitution was 12 (5, 27) months. Multivariate Cox proportional risk regression model analysis results showed that compared with those with initial ART at age ≥30 years, WHO clinical stage Ⅲ/Ⅳ illness, baseline BMI <18.50 kg/m2 and baseline CD4+T lymphocyte (CD4) counts <200 cells/µl, HIV infected MSM with initial ART at age <30 years, WHO clinical stageⅠ/Ⅱ illness, baseline BMI≥24.00 kg/m2 and baseline CD4 counts ≥200 cells/µl were more likely to have complete immune reconstitution. Conclusions: In the HIV infected MSM in Guangxi, failures to achieve moderate and complete immune reconstitution were observed. Surveillance and ART regimen should be improved for key populations, such as those with older age and low baseline CD4 counts.

ALYREF-JunD-SLC7A5 axis promotes pancreatic ductal adenocarcinoma progression through epitranscriptome-metabolism reprogramming and immune evasion

Pancreatic ductal adenocarcinoma (PDAC) is a kind of tumor lacking nutrients due to its poor vascularity and desmoplasia. Recent studies have shown that cancer cells might achieve growth advantage through epitranscriptome reprogramming. However, the role of m5C in PDAC was not fully understood. We found that Aly/REF export factor (ALYREF), a reader of m5C modification, was overexpressed in PDAC, and associated with bad prognosis. In addition, the ALYREF expression was negatively related to CD8+ T cells infiltration in clinical samples. ALYREF knockdown decreased tumor growth in vivo partly dependent of immunity. ALYREF silencing decreased SLC7A5 expression and subsequently inactivated mTORC1 pathway, resulting in decreased tumor proliferation. Mechanically, ALYREF specifically recognized m5C sites in JunD mRNA, maintained the stabilization of JunD mRNA and subsequently upregulated transcription of SLC7A5. Since SLC7A5 was a key transporter of large neutral amino acids (LNAAs), overexpression of SLC7A5 on tumor cells depleted amino acid in microenvironment and restricted CD8+ T cells function. Moreover, ALYREF-JunD-SLC7A5 axis was overexpressed and negatively related with survival through TMA assays. In conclusion, this research revealed the relationship between m5C modification, amino acid transportation and immune microenvironment. ALYREF might be a novel target for PDAC metabolic vulnerability and immune surveillance.

Ionic Bonding Without Directionality Facilitates Efficient Interfacial Bridging for Perovskite Solar Cells

Interface passivation through Lewis acid-base coordinate chemistry in perovskite solar cells (PSCs) is a universal strategy to reduce interface defects and hinder ion migration. However, the formation of coordinate covalent bonding demands strict directional alignment of coordinating atoms. Undoubtedly, this limits the selected range of the interface passivation molecules, because a successful molecular bridge between charge transport layer and perovskite bottom interface needs a well-placed molecular orientation. In this study, it is discovered that potassium ions can migrate to the hollow sites of multiple iodine ions from perovskite to form K-Ix ionic bonding, and the ionic bonds without directionality can support molecular backbone rotation to facilitate polar sites (carboxyl groups) chelating Pb at the bottom perovskite interface, finally forming a closed-loop bonding structure. The synergy of coordinate and ionic bonding significantly reduces interface defects, changes electric field distribution, and immobilizes iodine at the perovskite bottom interface, resulting in eliminating the hysteresis effect and enhancing the performance of PSCs. As a result, the corresponding devices achieve a high efficiency exceeding 24.5% (0.09 cm2 ), and a mini-module with 21% efficiency (12.4 cm2 ). These findings provide guidelines for designing molecular bridging strategies at the buried interface of PSCs.

Associations Between Plasma Orexin-A Level and Constipation in Cognitive Impairment

BACKGROUND

Constipation is a common symptom in dementia, and the cause is controversial. Rare clinical studies focused on plasma orexin-A levels and constipation in dementia.

OBJECTIVE

To evaluate the associations between orexin-A and constipation in patients with cognitive impairment.

METHODS

A total of 21 patients with mild cognitive impairment (MCI), 142 with Alzheimer's disease (AD), and 57 with Lewy body dementia (LBD) were conducted. Besides informant-based history, neurological examinations or neuropsychological assessments, plasma levels of orexin-A, and constipation were assessed. The associations between orexin-A and constipation were evaluated by logistic regression models.

RESULTS

There were 47/220 (21.36%) cognitive impairment patients having constipation, and the proportion of constipation in LBD (61.40%) was significantly higher than AD (5.63%) and MCI (19.05%). No significant age or sex differences in the prevalence of constipation were found in the MCI, AD, and LBD groups. We found the cognitive impairment patients with constipation had lower levels of plasma orexin-A [1.00 (0.86, 1.28) versus 1.29 (1.01, 1.50) ng/ml, p < 0.001] than those without. And the plasma levels of orexin-A were significantly associated with the occurrence of constipation after adjusting for all variables in all patients with cognitive impairment (OR = 0.151, 95% CI: 0.042-0.537, p = 0.003). And the same finding was more prominent in the LBD group (p = 0.048).

CONCLUSIONS

The decrease of plasma level of orexin-A is closely associated with the occurrence of constipation. Orexin-A has an intestinal protective effect and is involved in the gastrointestinal symptoms of patients with cognitive impairment.

CaCu3Mn2Te2O12: An Intrinsic Ferrimagnetic Insulator Prepared Under High Pressure

CaCu3Mn2Te2O12 was synthesized using high-temperature and high-pressure conditions. The compound possesses an A- and B site ordered quadruple perovskite structure in Pn3̅ symmetry with the charge combination of CaCu32+Mn22+Te26+O12. A ferrimagnetic phase transition originating from the antiferromagnetic interaction between A' site Cu2+ and B site Mn2+ ions is found to occur at TC ≈ 100 K. CaCu3Mn2Te2O12 also shows insulating electric conductivity. Optical measurement demonstrates the energy bandgap to be about 1.9 eV, in agreement with the high B site degree of chemical order between Mn2+ and Te6+. The first-principles theoretical calculations confirm the Cu2+(↓)-Mn2+(↑) ferrimagnetic coupling as well as the insulating nature with an up-spin direct bandgap. The current CaCu3Mn2Te2O12 provides an intriguing example of an intrinsic ferrimagnetic insulator with promising applications in advanced spintronic devices.

Controlling Selenization Equilibrium Enables High-Quality Kesterite Absorbers for Efficient Solar Cells

Kesterite Cu2ZnSn(S, Se)4 is considered one of the most competitive photovoltaic materials due to its earth-abundant and nontoxic constituent elements, environmental friendliness, and high stability. However, the preparation of high-quality Kesterite absorbers for photovoltaics is still challenging for the uncontrollability and complexity of selenization reactions between metal element precursors and selenium. In this study, we propose a solid-liquid/solid-gas (solid precursor and liquid/vapor Se) synergistic reaction strategy to precisely control the selenization process. By pre-depositing excess liquid selenium, we provide the high chemical potential of selenium to facilitate the direct and rapid formation of the Kesterite phase. The further optimization of selenium condensation and subsequent volatilization enables the efficient removal of organic compounds and thus improves charge transport in the absorber film. As a result, we achieve high-performance Kesterite solar cells with total-area efficiency of 13.6% (certified at 13.44%) and 1.09 cm2-area efficiency of 12.0% (certified at 12.1%).

Temporal Structures in Positron Spectra and Charge-Sign Effects in Galactic Cosmic Rays

We present the precision measurements of 11 years of daily cosmic positron fluxes in the rigidity range from 1.00 to 41.9 GV based on 3.4×10^{6} positrons collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The positron fluxes show distinctly different time variations from the electron fluxes at short and long timescales. A hysteresis between the electron fluxes and the positron fluxes is observed with a significance greater than 5σ at rigidities below 8.5 GV. On the contrary, the positron fluxes and the proton fluxes show similar time variation. Remarkably, we found that positron fluxes are modulated more than proton fluxes with a significance greater than 5σ for rigidities below 7 GV. These continuous daily positron fluxes, together with AMS daily electron, proton, and helium fluxes over an 11-year solar cycle, provide unique input to the understanding of both the charge-sign and mass dependencies of cosmic rays in the heliosphere.

Corrigendum: Use of autologous cord blood mononuclear cells infusion for the prevention of bronchopulmonary dysplasia in extremely preterm neonates: a study protocol for a placebo-controlled randomized multicenter trial [NCT03053076]

[This corrects the article DOI: 10.3389/fped.2020.00136.].

[Analysis of late-diagnosis and associated factors in newly reported HIV infections among men who have sex with men in Guangxi Zhuang Autonomous Region, 2005-2021]

Objective: To analyze the trend of late-diagnosis of HIV-infected men who have sex with men (MSM) before and after the AIDS Conquering Project in Guangxi Zhuang Autonomous Region (Guangxi) and its influencing factors, in order to find out the population groups that need priority intervention at the present stage. Methods: The HIV-infected MSM in Guangxi from 2005-2021 were selected from the National Integrated HIV/AIDS Control and Prevention Data System. The Joinpoint 4.9.1.0 software was used to test the time trend of late-diagnosis and non-late-diagnosis cases, and logistic regression was applied to analyze the factors influencing the proportion of late-diagnosis at each stage. Results: From 2005 to 2021, 5 764 HIV-infected MSM were reported in Guangxi from 2005 to 2021, with an overall late-diagnosis of 28.45% (1 640 cases). Under the 2015 baseline data as the boundary, the proportion of late-diagnosis cases showed a trend of sharp decline followed by stabilization from 2005 to 2015, average annual percent change= -6.90% (P<0.001). The effect of factors such as resident population, occupation as a farmer or worker, and sample originating from medical consultation on late-diagnosis changed considerably before and after the implementation of the project, and the factors influencing late-diagnosis at this stage were age, resident population, occupation as a farmer, worker or student. The factors influencing late-diagnosis at this stage are age, resident population, and occupation as a farmer, worker and a student. Conclusions: The proportion of late diagnosis cases of HIV-infected MSM in Guangxi decreased significantly before and after the project. However, late-diagnosis should not be neglected and precise prevention and control should be carried out for the resident population, farmers, workers or students.

Efficacy of Nimotuzumab plus Concurrent Chemo-Radiotherapy for Unresectable Esophageal Cancer: A Real-World Study

PURPOSE/OBJECTIVE(S)

The esophageal cancer ranked 7th in the morbidity of malignant cancer and the 6th contributed to carcinoma deaths. Most patients are diagnosed of advanced stage at first visiting. The 5-year survival rate of unresectable esophageal cancer is about 20% after the standard treatment of concurrent chemo-radiotherapy. Nimotuzumab, a humanized anti-EGFR antibody, has shown good efficacy and low toxicity in epithelial tumors. This two-center, real-world study evaluated the efficacy and safety of nimotuzumab combined with concurrent chemoradiotherapy in unresectable esophageal squamous cell carcinoma (ESCC).

MATERIALS/METHODS

Totally 503 eligible unresectable ESCC patients from Jan 2014 to Dec 2020 were included. 1:2 nearest neighbor propensity score matching (PSM) was performed to match the Nimo group (nimotuzumab plus concurrent chemo-radiotherapy) and CRT group (concurrent chemo-radiotherapy), and the covariates included age, gender, tumor location, lesion length, TNM stage, clinical stage, and radiotherapy dose. The primary endpoint was overall survival (OS). The secondary endpoints were progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR).

RESULTS

A total of 61 patients were in Nimo group which received nimotuzumab (200 mg/w, 4-6 weeks) combined with concurrent chemo-radiotherapy (chemotherapy: S-1/FP/TP/DP for 2-4 cycles; radiotherapy: 2DRT,3D-CRT or IMRT, 50-70 Gy in 25-35 fractions) and 107 patients in CRT group only received concurrent chemo-radiotherapy. The baseline characteristics were well balanced between the two groups. The efficacy of Nimo group was better than that of CRT group. The ORR was 85.2% vs. 71.0%, (P=0.037), the DCR was 98.4% vs. 91.6%, (P>0.05). The median PFS was 28.07 months vs. 19.54 months, and the 1-, 3- and 5-year PFS rates were 78.2% vs. 72.9%, 37.5% vs. 28.3%, and 29.1% vs. 21.3%, respectively (HR: 0.6860, 95% CI: 0.4902-0.9600, P=0.034). The median OS was 34.93 months vs. 24.30 months and the 1-, 3- and 5-year OS rates were 88.5% vs. 81.3%, 46.8% vs. 35.2% and 37.4% vs. 28.0%, respectively (HR: 0.6701, 95% CI: 0.4792-0.9372, P=0.024). The adverse events including radiation esophagitis, radiation pneumonitis, bone marrow suppression, nausea, vomiting, and rash were no significantly different between the two groups (P>0.05).

CONCLUSION

Nimotuzumab combined with concurrent chemo-radiotherapy improved the ORR, and prolonged PFS and OS in unresectable ESCC patients with a good tolerance.

Toward High Efficient Cu2 ZnSn(Sx ,Se1- x )4 Solar Cells: Break the Limitations of VOC and FF

Increasing the fill factor (FF) and the open-circuit voltage (V_OC ) simultaneously together with non-decreased short-circuit current density (J_SC ) are a challenge for highly efficient Cu₂ ZnSn(S,Se)₄ (CZTSSe) solar cells. Aimed at such target in CZTSSe solar cells, a synergistic strategy to tailor the recombination in the bulk and at the heterojunction interface has been developed, consisting of atomic-layer deposited aluminum oxide (ALD-Al₂ O₃ ) and (NH₄ )₂ S treatment. With this strategy, deep-level Cu_Zn defects are converted into shallower V_Cu defects and improved crystallinity, while the surface of the absorber is optimized by removing Zn- and Sn-related impurities and incorporating S. Consequently, the defects responsible for recombination in the bulk and at the heterojunction interface are effectively passivated, thereby prolonging the minority carrier lifetime and increasing the depletion region width, which promote carrier collection and reduce charge loss. As a consequence, the V_OC deficit decreases from 0.607 to 0.547 V, and the average FF increases from 64.2% to 69.7%, especially, J_SC does not decrease. Thus, the CZTSSe solar cell with the remarkable efficiency of 13.0% is fabricated. This study highlights the increased FF together with V_OC simultaneously to promote the efficiency of CZTSSe solar cells, which could also be applied to other photoelectronic devices.

Properties of Cosmic-Ray Sulfur and Determination of the Composition of Primary Cosmic-Ray Carbon, Neon, Magnesium, and Sulfur: Ten-Year Results from the Alpha Magnetic Spectrometer

We report the properties of primary cosmic-ray sulfur (S) in the rigidity range 2.15 GV to 3.0 TV based on 0.38×10^{6} sulfur nuclei collected by the Alpha Magnetic Spectrometer experiment (AMS). We observed that above 90 GV the rigidity dependence of the S flux is identical to the rigidity dependence of Ne-Mg-Si fluxes, which is different from the rigidity dependence of the He-C-O-Fe fluxes. We found that, similar to N, Na, and Al cosmic rays, over the entire rigidity range, the traditional primary cosmic rays S, Ne, Mg, and C all have sizeable secondary components, and the S, Ne, and Mg fluxes are well described by the weighted sum of the primary silicon flux and the secondary fluorine flux, and the C flux is well described by the weighted sum of the primary oxygen flux and the secondary boron flux. The primary and secondary contributions of the traditional primary cosmic-ray fluxes of C, Ne, Mg, and S (even Z elements) are distinctly different from the primary and secondary contributions of the N, Na, and Al (odd Z elements) fluxes. The abundance ratio at the source for S/Si is 0.167±0.006, for Ne/Si is 0.833±0.025, for Mg/Si is 0.994±0.029, and for C/O is 0.836±0.025. These values are determined independent of cosmic-ray propagation.

A General Strategy for Ordered Carrier Transport of Quasi-2D and 3D Perovskite Films for Giant Self-Powered Photoresponse and Ultrahigh Stability

Organic-inorganic hybrid perovskite materials have been focusing more attention in the field of self-powered photodetectors due to their superb photoelectric properties. However, a universal growth approach is required and challenging to realize vertically oriented growth and grain boundary fusion of 2D and 3D perovskite grains to promote ordered carrier transport, which determines superior photoresponse and high stability. Herein, a general thermal-pressed (TP) strategy is designed to solve the above issues, achieving uniaxial orientation and single-grain penetration along the film thickness direction. It constructs the efficient channel for ordered carrier transport between two electrodes. Combining of the improved crystal quality and lower trap-state density, the quasi-2D and 3D perovskite-based self-powered photodetector devices (with/without hole transport layer) all exhibit giant and stable photoresponse in a wide spectrum range and specific wavelength laser. For the MAPbI3-based self-powered photodetectors, the largest Rλ value is as high as 0.57 A W-1 at 760 nm, which is larger than most reported results. Meanwhile, under laser illumination (532 nm), the FPEA2MA4Pb5I16-based device exhibits a high responsivity (0.4 A W-1) value, which is one of the best results in 2DRP self-powered photodetectors. In addition, fast response, ultralow detection limit, and markedly improved humidity, optical and heat stabilities are clearly demonstrated for these TP-based devices.

Temporal Structures in Electron Spectra and Charge Sign Effects in Galactic Cosmic Rays

We present the precision measurements of 11 years of daily cosmic electron fluxes in the rigidity interval from 1.00 to 41.9 GV based on 2.0×10^{8} electrons collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The electron fluxes exhibit variations on multiple timescales. Recurrent electron flux variations with periods of 27 days, 13.5 days, and 9 days are observed. We find that the electron fluxes show distinctly different time variations from the proton fluxes. Remarkably, a hysteresis between the electron flux and the proton flux is observed with a significance of greater than 6σ at rigidities below 8.5 GV. Furthermore, significant structures in the electron-proton hysteresis are observed corresponding to sharp structures in both fluxes. This continuous daily electron data provide unique input to the understanding of the charge sign dependence of cosmic rays over an 11-year solar cycle.

Constructing an Interfacial Gradient Heterostructure Enables Efficient CsPbI3 Perovskite Solar Cells and Printed Minimodules

Severe nonradiative recombination originating from interfacial defects together with the pervasive energy level mismatch at the interface remarkably limits the performance of CsPbI₃ perovskite solar cells (PSCs). These issues need to be addressed urgently for high-performance cells and their applications. Herein, an interfacial gradient heterostructure based on low-temperature post-treatment of quaternary bromide salts for efficient CsPbI₃ PSCs with an impressive efficiency of 21.31% and an extraordinary fill factor of 0.854 is demonstrated. Further investigation reveals that Br^- ions diffuse into the perovskite films to heal undercoordinated Pb²⁺ and inhibit Pb cluster formation, thus suppressing nonradiative recombination in CsPbI₃ . Meanwhile, a more compatible interfacial energy level alignment resulting from Br^- gradient distribution and organic cations surface termination is also achieved, hence promoting charge separation and collection. Consequently, the printed small-size cell with an efficiency of 20.28% and 12 cm² printed CsPbI₃ minimodules with a record efficiency of 16.60% are also demonstrated. Moreover, the unencapsulated CsPbI₃ films and devices exhibit superior stability.

An Anomalous Electron Configuration Among 3d Transition Metal Atoms

Physical properties of materials are mainly determined by valence electron configurations, where different valence shells would induce divergent phenomena. In compounds containing Sc²⁺ , 3d electron occupancy is expected, the same as other transition metal atoms like Ti³⁺ . But this situation still awaits experimental verification in inorganic materials. Here, we selected ScS to measure the valence electron density and orbital population of Sc²⁺ through delicate quantitative convergent-beam electron diffraction. With the absence of 3d orbital features around Sc-atom sites and the nearly bare population of t_2g orbital, the unintuitive occupation of 4s orbital in Sc²⁺ is concluded. It should be the first time to report such a special electron configuration in a transition metal compound, in which 4s rather than 3d orbital is preferred. Our findings reveal the distinct behavior of Sc and probable ways to modulate material properties by controlling electron orbitals.

Costs of dementia with lewy bodies: A Chinese multicenter cross-sectional study

INTRODUCTION

Dementia with Lewy bodies (DLB) significantly increases the economic burden on caregivers and society, but few studies have focused on the costs. This study aims to evaluate the current economic costs of DLB and its related factors.

METHODS

A total of 193 patients diagnosed with probable DLB were consecutively enrolled from 6 memory clinics between August 2017 to July 2021. Data were collected from August to December of 2021, patients' per capita annual economic costs related to DLB in the year preceding the interview were evaluated, and factors related to the costs were assessed using regression analysis.

RESULTS

Patients with DLB led to per capita annual total costs of US $21,378.3 in 2021, with direct medical costs, direct non-medical costs and indirect costs of US $3471.4, US $3946.4 and US $13,960.5, respectively, accounting for 16.2%, 18.5% and 65.3%, of total costs. Factors related to the costs of DLB showed that impairments in activities of daily living (ADL) and caregivers' subjective burden had a greater impact on the total, direct medical and indirect costs.

CONCLUSION

The economic burden of DLB in China is huge, and indirect costs account for the largest proportion, serious impairment of the ADL and the subjective burden of caregivers, which possibly has a greater effect on costs. The substantial contributions made by family members and other unpaid caregivers of DLB should be fully recognized in strategic policy discussions and in case-level planning and assessments.

Oxygen Content Modulation Toward Highly Efficient Sb2Se3 Solar Cells

Vapor-transport deposition (VTD) method is the main technique for the preparation of Sb₂Se₃ films. However, oxygen is often present in the vacuum tube in such a vacuum deposition process, and Sb₂O₃ is formed on the surface of Sb₂Se₃ because the bonding of Sb-O is formed more easily than that of Sb-Se. In this work, the formation of Sb₂O₃ and thus the carrier transport in the corresponding solar cells were studied by tailoring the deposition microenvironment in the vacuum tube during Sb₂Se₃ film deposition. Combined by different characterization techniques, we found that tailoring the deposition microenvironment can not only effectively inhibit the formation of Sb₂O₃ at the CdS/Sb₂Se₃ interface but also enhance the crystalline quality of the Sb₂Se₃ thin film. In particular, such modification induces the formation of (hkl, l = 1)-oriented Sb₂Se₃ thin films, reducing the interface recombination of the subsequently fabricated devices. Finally, the Sb₂Se₃ solar cell with the configuration of ITO/CdS/Sb₂Se₃/Spiro-OMeTAD/Au achieves a champion efficiency of 7.27%, a high record for Sb₂Se₃ solar cells prepared by the VTD method. This work offers guidance for the preparation of high-efficiency Sb₂Se₃ thin-film solar cells under rough-vacuum conditions.

U-shaped association between dietary thiamine intake and new-onset diabetes: a nationwide cohort study

BACKGROUND

The association between dietary thiamine intake and the risk of diabetes remains unknown.

AIM

We aimed to evaluate the relation of dietary thiamine intake with new-onset diabetes and examine possible effect modifiers.

DESIGN

Prospective cohort study.

METHODS

A total of 16 272 participants who were free of diabetes at baseline were enrolled from China Health and Nutrition Survey (CHNS). Dietary nutrients intake information was collected by 3-day dietary recalls in addition to using a 3-day food-weighed method to assess cooking oil and condiment consumption. New-onset diabetes was defined as a fasting blood glucose ≥7.0 mmol/l or a glycated haemoglobin (HbA1c) ≥6.5% (48 mmol/mol) or diagnosed by a physician during the follow-up.

RESULTS

During a median follow-up duration of 9.0 years, new-onset diabetes occurred in 1101 participants. Overall, the association between dietary thiamine intake and new-onset diabetes followed a U-shape (P for non-linearity <0.001). Consistently, when thiamine intake was assessed as quartiles, compared with those in the 2-3 quartiles (0.75 to 1.10 mg/day), the significantly higher risks of new-onset diabetes were found in participants in the first quartile [adjusted hazard ratio (HR), 1.33; 95% confidence interval (CI): 1.10, 1.61] and the fourth quartile (adjusted HR, 1.39; 95% CI: 1.17, 1.67). Similar results were found when further adjusting for the intake of other major nutrients or food groups; or using the propensity score weighting to control the imbalance of covariates.

CONCLUSION

Our results suggested that there was a U-shape association between dietary thiamine intake and new-onset diabetes in general Chinese adults, with a minimal risk at 0.75-1.10 mg/day.

Manipulating the Migration of Iodine Ions via Reverse-Biasing for Boosting Photovoltaic Performance of Perovskite Solar Cells

Perovskite solar cells (PSCs) are being developed rapidly and exhibit greatly potential commercialization. Herein, it is found that the device performance can be improved by manipulating the migration of iodine ions via reverse-biasing, for example, at -0.4 V for 3 min in dark. Characterizations suggest that reverse bias can increase the charge recombination resistance, improve carrier transport, and enhance built-in electric field. Iodine ions including iodine interstitials in perovskites are confirmed to migrate and accumulate at the SnO₂ /perovskite interface under reverse-basing, which fill iodine vacancies at the interface and interact with SnO₂ . First-principles calculations suggest that the SnO₂ /perovskite interface with less iodine vacancies has a stronger interaction and higher charge transfer, leading to larger built-in electric field and improved charge transport. Iodine ions that may pass through the SnO₂ /perovskite interface are also confirmed to be able to interact with Sn⁴⁺  and passivate oxygen vacancies on the surface of SnO₂ . Consequently, an efficiency of 23.48% with the open-circuit voltage (V_oc ) of 1.16 V is achieved for PSCs with reverse-biasing, as compared with the initial efficiency of 22.13% with a V_oc  of 1.10 V. These results are of great significance to reveal the physics mechanism of PSCs under electric field.

A Versatile Molten-Salt Induction Strategy to Achieve Efficient CsPbI3 Perovskite Solar Cells with a High Open-Circuit Voltage >1.2 V

All-inorganic CsPbI₃ perovskite has emerged as an important photovoltaic material due to its high thermal stability and suitable bandgap for tandem devices. Currently, the cell performance of CsPbI₃ solar cells is mainly subject to a large open-circuit voltage (V_OC ) deficit. Herein, a multifunctional room-temperature molten salt, dimethylamine acetate (DMAAc) is demonstrated, which not only directly acts as a solvent for precursor solutions, but also regulates the phase conversion process of the CsPbI₃ film for high-efficiency photovoltaics. DMAAc can stabilize the DMAPbI₃ structure and eliminate the Cs₄ PbI₆ intermediate phase, which is easily spatially segregated. Meanwhile, a new homogeneous intermediate phase DMAPb(I,Ac)₃ is formed, which finally affords high-quality CsPbI₃ films. With this approach, the charge capture activity of defects in the CsPbI₃ film is significantly suppressed. Consequently, a V_OC of 1.25 V and >21% power conversion efficiency are achieved, which is the record highest reported thus far. This intermediate phase-regulation strategy is believed to be applicable to other perovskite material systems.

Simultaneously Enhancing Exciton/Charge Transport in Organic Solar Cells by an Organoboron Additive

Efficient exciton diffusion and charge transport play a vital role in advancing the power conversion efficiency (PCE) of organic solar cells (OSCs). Here, a facile strategy is presented to simultaneously enhance exciton/charge transport of the widely studied PM6:Y6-based OSCs by employing highly emissive trans-bis(dimesitylboron)stilbene (BBS) as a solid additive. BBS transforms the emissive sites from a more H-type aggregate into a more J-type aggregate, which benefits the resonance energy transfer for PM6 exciton diffusion and energy transfer from PM6 to Y6. Transient gated photoluminescence spectroscopy measurements indicate that addition of BBS improves the exciton diffusion coefficient of PM6 and the dissociation of PM6 excitons in the PM6:Y6:BBS film. Transient absorption spectroscopy measurements confirm faster charge generation in PM6:Y6:BBS. Moreover, BBS helps improve Y6 crystallization, and current-sensing atomic force microscopy characterization reveals an improved charge-carrier diffusion length in PM6:Y6:BBS. Owing to the enhanced exciton diffusion, exciton dissociation, charge generation, and charge transport, as well as reduced charge recombination and energy loss, a higher PCE of 17.6% with simultaneously improved open-circuit voltage, short-circuit current density, and fill factor is achieved for the PM6:Y6:BBS devices compared to the devices without BBS (16.2%).

Quantitation study on VOC emissions and their reduction potential for coking industry in China: Based on in-situ measurements on treated and untreated plants

Currently, the characteristics of volatile organic compounds (VOC) released from coking industry are still vague, and the widely used VOC emission factors (EFs) were still from the measurements of 1990s. Hence, focusing on coking industry, we conducted an in-situ measurement campaign in several typical plants, developed a set of VOC EFs for various release units, and estimated the current emission amounts and future reduction potentials of VOC in China. The measurements show that the levels of VOC in stationary units were 63.82-9563.93 μg·m^-3, and those surrounding fugitive units were 111.37-1436.36 μg·m^-3. VOC emissions from stationary units were directly calculated, which deducing EFs of 11.57, 15.51, 127.13, 0.28, 0.16 g·t^-1 coke respectively for coke charging, coke pushing, coke oven chimney, dry quenching, and wastewater treatment processes. Meanwhile, VOC emissions from fugitive units were simulated following the inverse dispersion method, which achieving EFs of 443.34 ± 66.31, 352.12 ± 65.81, and 718.56 ± 132.69 g·t^-1 coke respectively for the coke oven leakage, byproduct recovery with VOC treatment system, and byproduct recovery without VOC treatment system. Generally, the coking plants installing VOC treatment system had total VOC EF of 953.76 g·t^-1 coke, about 37.1% lower than those never considering VOC treatment (1516.25 g·t^-1 coke). According to these developed EFs, the VOC emission amount from coking industry in China were estimated, slightly decreasing from 623.54 to 578.17 Gg per year, although the coke production increasing from 410.86 to 418.26 Tg during 2015-2019. In future, according to the national industrial policies, regulations and standards, technical guidelines, the VOC reduction potential of this industry in China could reach 336.9 Gg, to which headstream adjustment, process improvement, and end-of-pipe control contributed about 21.4%, 31.6%, and 47.0%, respectively.

Association between hemoglobin level and cognitive profile in old adults: A cross-sectional survey

OBJECTIVE

In the present study, the association between Hemoglobin (HGB) level and cognitive profile was investigated and whether it affected the dementia risk in older adults.

METHODS

A cross-sectional population-based survey that included 3519 individuals ≥65 years of age was conducted in 2019. Basic demographic characteristics were collected. The neuropsychological assessments and blood tests were administered to evaluate cognition and HGB level. Generalized additive models were used to analyze the non-linear association between HGB levels and cognitive function. Logistics regression models were utilized to analyze the associations between HGB level and dementia risk.

RESULTS

Overall, 459 (12.7%) participants were diagnosed with dementia and there were more females (54.7%) than males (45.3%). The number of subjects with anemia (3%) or hyperhemoglobinemia (5.2%) was higher than participants with normal HGB level. A visual representation of the relationship between HGB level and Mini-Mental State Examination (MMSE) score showed an inverted U-curve, which is more evident in female. Logistics regression models showed that anemia (odds ratio, OR = 1.826, 95% confidence interval, CI: 1.166-2.860, p < 0.01), but not hyperhemoglobinemia, significantly increased the risk of dementia. These trends were not the same for males and females. An abnormal HGB level had greater effects in females, resulting in higher risk of dementia for females with anemia or hyperhemoglobinemia than subjects with normal HGB level including males.

CONCLUSION

Both low and high HGB levels can lead to cognitive decline in the incidence of dementia, indicating an inverted U-shaped curve association may exist between HGB level and global cognitive profile.

Ge Bidirectional Diffusion to Simultaneously Engineer Back Interface and Bulk Defects in the Absorber for Efficient CZTSSe Solar Cells

Aiming at a large open-circuit voltage (V_OC ) deficit in Cu₂ ZnSn(S,Se)₄ (CZTSSe) solar cells, a new and effective strategy to simultaneously regulate the back interface and restrain bulk defects of CZTSSe absorbers is developed by directly introducing a thin GeO₂ layer on Mo substrates. Power conversion efficiency (power-to-efficiency) as high as 13.14% with a V_OC of 547 mV is achieved for the champion device, which presents a certified efficiency of 12.8% (aperture area: 0.25667 cm² ). Further investigation reveals that Ge bidirectional diffusion simultaneously occurs toward the CZTSSe absorber and MoSe₂ layer at the back interface while being selenized. That is, some Ge element from the GeO₂ diffuses into the CZTSSe absorber layer to afford Ge-doped absorbers, which can significantly reduce the defect density and band tailing, and facilitate quasi-Fermi level split by relatively higher hole concentration. Meanwhile, a small amount of Ge element also participates in the formation of MoSe₂ at the back interface, thus enhancing the work function of MoSe₂ and effectively separating photoinduced carriers. This work highlights the synergistic effect of Ge element toward the bulk absorber and the back interface and also provides an easy-handling way to achieve high-performance CZTSSe solar cells.

Elevated Plasma Orexin-A Levels in Prodromal Dementia with Lewy Bodies

BACKGROUND

Studies on plasma orexin-A levels in prodromal dementia with Lewy bodies (DLB) and the relationship with clinical manifestations are rare.

OBJECTIVE

To assess plasma orexin-A levels and evaluate the correlation with clinical features in patients with mild cognitive impairment with Lewy bodies (MCI-LB) and DLB.

METHODS

Plasma orexin-A levels were measured in 41 patients with MCI-LB, 53 with DLB, and 48 healthy controls (HCs). Informant-based history, neurological examinations, neuropsychological assessments, laboratory tests, and neuroimaging were collected and the correlation between orexin-A and various indicators evaluated.

RESULTS

Plasma orexin-A levels in patients with MCI-LB (1.18±0.33 ng/mL, p = 0.014) or DLB (1.20±0.44 ng/mL, p = 0.011) were significantly higher than in HCs (1.02±0.32 ng/mL) and associated with gender and age. DLB patients with fluctuating cognition (FC) (1.01±0.23 versus 1.31±0.50, p = 0.007) or parkinsonism (PARK) (0.98±0.19 versus 1.25±0.47, p = 0.030) had significantly lower plasma orexin-A levels than subjects without FC or PARK. Plasma orexin-A levels were significantly negatively correlated with irritability and UPDRS-III scores and significantly positively correlated with disinhibition scores.

CONCLUSION

This is the first report in which elevated plasma orexin-A levels were observed in patients with MCI-LB or DLB. In addition, lower orexin-A levels were found in patients with DLB and FC or PARK compared with HCs. The plasma orexin-A levels were associated with the presence of core features and motor and neuropsychiatric symptoms in patients with MCI-LB and DLB.

Properties of Daily Helium Fluxes

We present the precision measurement of 2824 daily helium fluxes in cosmic rays from May 20, 2011 to October 29, 2019 in the rigidity interval from 1.71 to 100 GV based on 7.6×10^{8} helium nuclei collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The helium flux and the helium to proton flux ratio exhibit variations on multiple timescales. In nearly all the time intervals from 2014 to 2018, we observed recurrent helium flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. In the entire time period, we found that below ∼7  GV the helium flux exhibits larger time variations than the proton flux, and above ∼7  GV the helium to proton flux ratio is time independent. Remarkably, below 2.4 GV a hysteresis between the helium to proton flux ratio and the helium flux was observed at greater than the 7σ level. This shows that at low rigidity the modulation of the helium to proton flux ratio is different before and after the solar maximum in 2014.

Temperature-Reliable Low-Dimensional Perovskites Passivated Black-Phase CsPbI3 toward Stable and Efficient Photovoltaics

Low-dimensional (LD) perovskites can effectively passivate and stabilize 3D perovskites for high-performance perovskite solar cells (PSCs). Regards CsPbI₃ -based PSCs, the influence of high-temperature annealing on the LD perovskite passivation effect has to be taken into account due to fact the black-phase CsPbI₃ crystallization requires high-temperature treatment, however, which has been rarely concerned so far. Here, the thermal stability of LD perovskites based on three hydrophobic organic ammonium salts and their passivation effect toward CsPbI₃ and the whole device performance, have been investigated. It is found that, phenyltrimethylammonium iodide (PTAI) and its corresponding LD perovskites exhibit excellent thermal stability. Further investigation reveals that PTAI-based LD perovskites are mainly distributed at grain boundaries, which not only enhances the phase stability of CsPbI₃ but also effectively suppresses non-radiative recombination. As a consequence, the champion PSC device based on CsPbI₃ exhibits a record efficiency of 21.0 % with high stability.

The vascular risk factors and vascular neuropathology in subjects with autopsy-confirmed dementia with Lewy bodies

BACKGROUND

The frequency of vascular risk factors (VRFs) and the relationship between vascular pathology and cognitive function in neurodegenerative disease remains incompletely understood.

OBJECTIVE

The purpose of this study was to describe the frequency of VRFs and vascular pathology and explore the relationship between vascular pathology and cognitive function in dementia with Lewy bodies (DLB).

METHODS

This study included 363 autopsy-confirmed DLB and 753 Alzheimer's disease (AD) patients from the National Alzheimer's Coordinating Center (NACC) database. We used chi-squared test and analysis of variance to compare the VRFs and related factors in DLB and AD. Multinomial logistic regression and Spearman's correlation test were used to examine the relationship between vascular pathology and cognitive function.

RESULTS

No significant differences of VRFs were identified between DLB and AD. Alzheimer's disease patients had higher rates of microinfarcts (23.5% vs. 16.3%, p = 0.005) and moderate to severe amyloid angiopathy (45.9% vs. 36.1%, p = 0.002). In DLB patients, only cerebral amyloid angiopathy (CAA) pathology was negatively correlated with memory domain (r = -0.263, p < 0.001) and language (r = -0.112,p = 0.034). The rates of APOE ε4 allele carriers (60.0% vs. 44.9%, p = 0.004) and CAA pathology (45.9% vs.23.4%, p < 0.001) were much higher in the group with an intermediate likelihood of DLB than in the group with a high likelihood. There was a negative correlation between CAA pathology and memory (logical memory) in the group with an intermediate likelihood of DLB.

CONCLUSION

No difference of VRFs was identified between autopsy-confirmed DLB and AD. Cerebral amyloid angiopathy was shown to be an important pathology in DLB, which specifically correlated with memory and language. The groups with high and intermediate likelihood of DLB differed in terms of CAA pathology, and CAA pathology may play an important role in the development of DLB.

High-efficiency (>20%) planar carbon-based perovskite solar cells through device configuration engineering

Carbon-based perovskite solar cells (C-PSCs) have attracted widespread research interest because of their excellent stability. However, the power conversion efficiency (PCE) of C-PSCs, especially planar C-PSCs, lags far behind the certified efficiency (25.5%) of metal-based PSCs. The simple architecture of planar C-PSCs imparts stringent requirements for device configuration. In this study, we fabricated high-performance planar C-PSCs through device configuration engineering in terms of the perovskite active layer and carbon electrode. Through the combination of component and additive engineering, the crystallization and absorption profiles of perovskite active layer have been improved, which afforded sufficient photogenerated carriers and decreased nonradiative recombination. Furthermore, the mechanical and physical properties of carbon electrode were evaluated comprehensively to regulate the back-interface contact. Based on the compromise of the flexibility and conductivity of carbon film, an excellent back-interface contact has been formed, which promoted fast interface charge transfer, thereby decreasing interface recombination and improving carrier collection efficiency. Finally, the as-prepared devices achieved a remarkable PCE of up to 20.04%, which is a record-high value for planar C-PSCs. Furthermore, the as-prepared devices exhibited excellent long-term stability. After storage for 1000 h at room temperature and 25% relative humidity without encapsulation, the as-prepared device retained 94% of its initial performance.

Pressure-Enhanced Vertical Orientation and Compositional Control of Ruddlesden-Popper Perovskites for Efficient and Stable Solar Cells and Self-Powered Photodetectors

It is well-known that two-dimensional Ruddlesden-Popper (2DRP) perovskite has higher stability than three-dimensional counterparts. However, fundamental issues still exist in the vertical orientation and phase composition as well as phase distribution. Here, obvious control of the film quality of 2DRP PEA₂MA₄Pb₅I₁₆ (n = 5) perovskite is demonstrated via a thermal-pressed (TP) effect. The crystallinity, morphology, phase composition, and optoelectronic features unequivocally illustrate that the TP effect achieves a larger gain size, a smoother surface, an effectively vertical orientation, a relatively pure phase with a large n value, a gradient distribution of quantum wells, and enhanced interlayer interaction. These film and interface features lead to markedly enhanced charge transport/extraction and lower trap density. Accordingly, the TP-based perovskite film device delivers a power conversion efficiency of 15.14%, far higher than that of the control film device (11.10%) because of significant improvements in open-circuit voltage and short-circuit current. More importantly, it also presents excellent hydrophobicity, illumination stability, and environmental stability. In addition, the 2D perovskite self-powered photodetector also exhibits high responsivity (0.25 A W^-1) and specific detectivity (1.4 × 10¹² Jones) at zero bias.

Impact of the COVID-19 Pandemic and Lockdown on Anxiety, Depression and Nursing Burden of Caregivers in Alzheimer's Disease, Dementia With Lewy Bodies and Mild Cognitive Impairment in China: A 1-Year Follow-Up Study

BACKGROUND

Many countries have adopted lockdown strategies to prevent the spread of COVID-19. The goal of this study was to investigate the effects of the pandemic on anxiety, depression and care burden in caregivers of nursing patients with Alzheimer's disease (AD), Dementia with Lewy Bodies (DLB) and Mild Cognitive Impairment (MCI), over a one-year period.

METHODS

We collected data on consecutive patients and their caregivers recruited at T0 (from 30 September to 31 December 2019) before the pandemic of COVID-19 at the memory clinic of Tianjin Huanhu Hospital. The patients and caregivers were followed up on face-to-face at T1 (from 30 September to 31 December 2020) during the pandemic to assess changes in physical activity, social contact, sleep quality, caregiver burden, anxiety and depression.

RESULTS

A total of 105 AD, 22 DLB and 50 MCI patients and caregivers were enrolled. A total of 36.6 % of the AD, 81.6% of the DLB, 38% of the MCI caregivers had worsening ZBI, whereas 31.7 % of the AD, 54.4% of the DLB, 26 % of the MCI caregivers had worsening GAD-7, and 29.6 % of the AD, 54.4% of the DLB, and 32 % of the MCI caregivers had worsening PHQ-9. DLB caregivers exhibited a rapid deterioration of ZBI (by 4.27 ± 5.43, P < 0.001), GAD-7 (by 2.23 ± 3.26, P = 0.003) and PHQ-9 (by 1.32 ± 2.25, P = 0.003) compared to AD and MCI caregivers.

CONCLUSION

Social isolation, physical inactivity and sleep disturbance after lockdown for at least 12 months were significantly related to increased caregiver burden and worsened psychological states of caregivers of AD, DLB and MCI sufferers, especially among DLB caregivers.

Periodicities in the Daily Proton Fluxes from 2011 to 2019 Measured by the Alpha Magnetic Spectrometer on the International Space Station from 1 to 100 GV

We present the precision measurement of the daily proton fluxes in cosmic rays from May 20, 2011 to October 29, 2019 (a total of 2824 days or 114 Bartels rotations) in the rigidity interval from 1 to 100 GV based on 5.5×10^{9} protons collected with the Alpha Magnetic Spectrometer aboard the International Space Station. The proton fluxes exhibit variations on multiple timescales. From 2014 to 2018, we observed recurrent flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. The rigidity dependence of the 27-day periodicity is different from the rigidity dependences of 9-day and 13.5-day periods. Unexpectedly, the strength of 9-day and 13.5-day periodicities increases with increasing rigidities up to ∼10  GV and ∼20  GV, respectively. Then the strength of the periodicities decreases with increasing rigidity up to 100 GV.

Two-Step Annealing CZTSSe/CdS Heterojunction to Improve Interface Properties of Kesterite Solar Cells

The post-heating treatment of the CZTSSe/CdS heterojunction can enhance the interfacial properties of kesterite Cu₂ZnSn(S,Se)₄ (CZTSSe) solar cells. In this regard, a two-step annealing method was developed to enhance the heterojunction quality for the first time. That is, a low-temperature (90 °C) process was introduced before the high-temperature treatment, and 12.3% efficiency of CZTSSe solar cells was achieved. Further investigation revealed that the CZTSSe/CdS heterojunction band alignment with a smaller spike barrier can be realized by the two-step annealing treatment, which assisted in carrier transportation and reduced the charge recombination loss, thus enhancing the open-circuit voltage (V_OC) and fill factor (FF) of the devices. In addition, the two-step annealing could effectively avoid the disadvantages of direct high-temperature treatment (such as more pinholes on CdS films and excess element diffusion), improve the CdS crystallization, and decrease the defect densities within the device, especially interfacial defects. This work provides an effective method to improve the CZTSSe/CdS heterojunction properties for efficient kesterite solar cells.

Erratum: Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen [Phys. Rev. Lett. 127, 021101 (2021)]

This corrects the article DOI: 10.1103/PhysRevLett.127.021101.

Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen

We report the properties of sodium (Na) and aluminum (Al) cosmic rays in the rigidity range 2.15 GV to 3.0 TV based on 0.46 million sodium and 0.51 million aluminum nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. We found that Na and Al, together with nitrogen (N), belong to a distinct cosmic ray group. In this group, we observe that, similar to the N flux, both the Na flux and Al flux are well described by the sums of a primary cosmic ray component (proportional to the silicon flux) and a secondary cosmic ray component (proportional to the fluorine flux). The fraction of the primary component increases with rigidity for the N, Na, and Al fluxes and becomes dominant at the highest rigidities. The Na/Si and Al/Si abundance ratios at the source, 0.036±0.003 for Na/Si and 0.103±0.004 for Al/Si, are determined independent of cosmic ray propagation.

Efficient (>20 %) and Stable All-Inorganic Cesium Lead Triiodide Solar Cell Enabled by Thiocyanate Molten Salts

Besides widely used surface passivation, engineering the film crystallization is an important and more fundamental route to improve the performance of all-inorganic perovskite solar cells. Herein, we have developed a urea-ammonium thiocyanate (UAT) molten salt modification strategy to fully release and exploit coordination activities of SCN^- to deposit high-quality CsPbI₃ film for efficient and stable all-inorganic solar cells. The UAT is derived by the hydrogen bond interactions between urea and NH₄ ⁺ from NH₄ SCN. With the UAT, the crystal quality of the CsPbI₃ film has been significantly improved and a long single-exponential charge recombination lifetime of over 30 ns has been achieved. With these benefits, the cell efficiency has been promoted to over 20 % (steady-state efficiency of 19.2 %) with excellent operational stability over 1000 h. These results demonstrate a promising development route of the CsPbI₃ related photoelectric devices.

Eliminating the electric field response in a perovskite heterojunction solar cell to improve operational stability

Intrinsic and extrinsic ion migration is a very large threat to the operational stability of perovskite solar cells and is difficult to completely eliminate due to the low activation energy of ion migration and the existence of internal electric field. We propose a heterojunction route to help suppress ion migration, thus improving the operational stability of the cell from the perspective of eliminating the electric field response in the perovskite absorber. A heavily doped p-type (p⁺) thin layer semiconductor is introduced between the electron transporting layer (ETL) and perovskite absorber. The heterojunction charge depletion and electric field are limited to the ETL and p⁺ layers, while the perovskite absorber and hole transporting layer remain neutral. The p⁺ layer has a variety of candidate materials and is tolerant of defect density and carrier mobility, which makes this heterojunction route highly feasible and promising for use in practical applications.

CdS Induced Passivation toward High Efficiency and Stable Planar Perovskite Solar Cells

In perovskite solar cells, the halide vacancy defects on the perovskite film surface/interface will instigate charge recombination, leading to a decrease in cell performance. In this study, cadmium sulfide (CdS) has been introduced into the precursor solution to reduce the halide vacancy defects and improve the cell performance. The highest efficiency of the device reaches 21.62%. Density functional theory calculation reveals that the incorporated Cd²⁺ ions can partially replace Pb²⁺ ions, thus forming a strong Cd-I bond and effectively reducing iodide vacancy defects (V_I); at the same time, the loss of the charge recombination is significantly reduced because V_I is filled by S^2- ions. Besides, the substitution of Cd²⁺ for Pb²⁺ could increase the generation of PbI₂, which can further passivate the grain boundary. Therefore, the stability of the cells, together with the efficiency of the power conversion efficiencies (PCEs), is also improved, maintaining 87.5% of its initial PCEs after being irradiated over 410 h. This work provides a very effective strategy to passivate the surface/interface defects of perovskite films for more efficient and stable optoelectronic devices.

Properties of Heavy Secondary Fluorine Cosmic Rays: Results from the Alpha Magnetic Spectrometer

Precise knowledge of the charge and rigidity dependence of the secondary cosmic ray fluxes and the secondary-to-primary flux ratios is essential in the understanding of cosmic ray propagation. We report the properties of heavy secondary cosmic ray fluorine F in the rigidity R range 2.15 GV to 2.9 TV based on 0.29 million events collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. The fluorine spectrum deviates from a single power law above 200 GV. The heavier secondary-to-primary F/Si flux ratio rigidity dependence is distinctly different from the lighter B/O (or B/C) rigidity dependence. In particular, above 10 GV, the F/Si/B/O ratio can be described by a power law R^{δ} with δ=0.052±0.007. This shows that the propagation properties of heavy cosmic rays, from F to Si, are different from those of light cosmic rays, from He to O, and that the secondary cosmic rays have two classes.