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The intraseasonal oscillations (30–100 days, ISO) in the MLT (mesosphere and lower thermosphere) horizontal wind are investigated based on observations from the Mengcheng meteor radar. There is a clear seasonal variation in ISO in the horizontal wind at 80 km, which is strongest during the winter and weakest during the summer. At 100 km, ISO occurs throughout most of the year except winter, and there are significant differences in periods and amplitudes from year to year. From 2015 to 2016, ISOs with periods of 40–60 days were present in the 100 km horizontal wind, whereas none were simultaneously observed in the 80 km horizontal wind. Cross wavelets were used to study the relationship between ISO in the MLT region and ISO in the lower atmosphere. Some of the ISO activity is linked to tropospheric tropical convective activity, but the ISO connections with that in tropospheric convection are not consistent in the upper mesosphere and in the lower thermosphere. [ABSTRACT FROM AUTHOR]

Obesity is a common chronic metabolic disease that induces chronic systemic inflammation in the body, eventually leading to related complications such as insulin resistance (IR), type 2 diabetes mellitus, and metabolic syndromes such as cardiovascular disease. Exosomes transfer bioactive substances to neighboring or distal cells through autosomal, paracrine, or distant secretion, regulating the gene and protein expression levels of receptor cells. In this study, we investigated the effect of mouse bone marrow mesenchymal stem cell‐derived exosomes (BMSC‐Exos) on high‐fat diet obese mice and mature 3T3‐L1 adipocyte models of IR. BMSC‐Exo treatment of obese mice promoted their metabolic homeostasis, including reduction of obesity, inhibition of M1‐type proinflammatory factor expression, and improvement of insulin sensitivity. In vitro analysis revealed that BMSC‐Exos improved IR and lipid droplet accumulation in mature 3T3‐L1 adipocytes treated with palmitate (PA). Mechanistically, BMSC‐Exos cause increased glucose uptake and improved IR in high‐fat chow‐fed mice and PA‐acting 3T3‐L1 adipocytes by activating the phosphoinositide 3‐kinases/protein kinase B (PI3K/AKT) signaling pathway and upregulating glucose transporter protein 4 (GLUT4) expression. This study offers a new perspective for the development of treatments for IR in obese and diabetic patients. [ABSTRACT FROM AUTHOR]

Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) with earth‐abundant and environmental‐benign constituents has been regarded as a promising solar energy harvesting material for green and cost‐effective photovoltaic applications. The record efficiency of CZTSSe solar cells has recently been refreshed twice after years‐long stagnation, keeping it in the spotlight. Nevertheless, the champion efficiency of 13.6% is still far behind its counterpart Cu(In,Ga)Se2 (CIGS) (23.35%) despite being endowed with a similar electronic structure and nearly‐identical device architecture. In fact, CZTSSe solar cells are more susceptible to non‐radiative recombination at bulk and interfaces, which must be improved for further efficiency advancement. In this review, the state‐of‐art strategies to enhance the power conversion efficiency of CZTSSe solar cells are summarized and discussed, with focus given to three critical device regions i) kesterite absorber, ii) buffer/kesterite interface, and iii) kesterite/back contact interface. With the further elucidation of the latest progress and disclosure of fundamental mechanisms, novel insights toward high‐efficiency kesterite solar cells are proposed. [ABSTRACT FROM AUTHOR]

Abstract As an important step towards the realisation of silicon-based tandem solar cells using silicon quantum dots embedded in a silicon dioxide (SiO2) matrix, single-junction silicon quantum dot (Si QD) solar cells on quartz substrates have been fabricated. The total thickness of the solar cell material is 420 nm. The cells contain 4 nm diameter Si quantum dots. The impacts of post-metallisation treatments such as phosphoric acid (H3PO4) etching, nitrogen (N2) gas anneal and forming gas (Ar: H2) anneal on the cells’ electrical and photovoltaic properties are investigated. The Si QD solar cells studied in this work have achieved an open circuit voltage of 410 mV after various processes. Parameters extracted from dark I–V, light I–V and circular transfer length measurement (CTLM) suggest limiting mechanism in the Si QD solar cell operation and possible approaches for further improvement.

Earth‐abundant and air‐stable Cu2BaSnS4−xSex (CBTSSe) and related thin‐film absorbers are regarded as prospective options to meet the increasing demand for low‐cost solar cell deployment. Devices based on vacuum‐deposited CBTSSe absorbers have achieved record power conversion efficiency (PCE) of 5.2% based on a conventional device structure using CdS buffer and i‐ZnO/indium tin oxide (ITO) window layers, with open‐circuit voltage (VOC) posing the major bottleneck for improving solar cell performance. The current study demonstrates a >20% improvement in VOC (from 0.62 to 0.75 V) and corresponding enhancement in PCE (from 5.1% to 6.2% without antireflection coating; to 6.5% with MgF2 antireflection coating) for solution‐deposited CBTSSe solar cells. This performance improvement is realized by introducing an alternative successive ionic layer adsorption and reaction‐deposited Zn1−xCdxS buffer combined with sputtered Zn1−xMgxO/Al‐doped ZnO window/top contact layer, which offers lower electron affinities relative to the conventional CdS/i‐ZnO/ITO stack and better matching with the low electron affinity of CBTSSe. A combined experimental (temperature‐ and light intensity‐dependent VOC measurements) and device simulation (SCAPS‐1D) evaluation points to the importance of addressing relative band offsets for both the buffer and window layers relative to the absorber in mitigating interfacial recombination and optimizing CBTSSe solar cell performance. [ABSTRACT FROM AUTHOR]

Effectively incorporating alkali metals or alternative isovalent cations into Cu2ZnSnS4 (CZTS) is considered one of the most promising strategies for realizing a step‐change improvement in the photovoltaic device performance. Herein, the local distribution of Na and Cd by a moisture‐assisted postdeposition annealing (MAPDA) treatment combined with a subsequent heterojunction heat treatment is manipulated. The MAPDA treatment facilitates the controllable reduction of the Na concentration, thus promoting the spontaneous diffusion of Cd into the heterojunction region. A subsequent 150 °C low‐temperature heterojunction heat treatment after MAPDA treatment enables further modification of Cd and Na distributions, leading to significantly enhanced optoelectronic properties at the CZTS/CdS heterojunction and greatly improved device performance with a peak conversion efficiency of 9.40%. The modified heterojunction significantly improves quasi‐Fermi‐level splitting under low‐photon injection, making CZTS solar cells more feasible in low‐light applications. This work provides an effective approach to simultaneously manipulate the distribution of Na and Cd, enabling pronounced modification of the heterojunction quality of CZTS solar cells and boost of conversion efficiencies. Insights gleaned herein may also be applicable to manipulating other critical trace elements in chalcogenide materials in general. [ABSTRACT FROM AUTHOR]

Antimony sulfide (Sb2S3) is a promising wide‐bandgap photovoltaic material, and a potential top‐cell candidate for next‐generation Si‐based tandem solar cells. The most widely used electron transport layers in Sb2S3 solar cells are TiO2 and CdS, which present an obvious performance variation in open‐circuit voltage (VOC) and short current (Jsc). However, the mechanisms behind the performance disparity because of the electron transport layer (ETL) have not been disclosed. Herein, a comprehensive comparative study of using TiO2 and CdS as the electron transport layers in Sb2S3 solar cells is presented, which covers their influence on preferential crystal orientation, band alignment, interface, and bulk defects. It is found that the CdS ETL results in less interfacial defects and more favorable band alignment, enabling a higher VOC, while the high resistance of the CdS film and parasitic light absorption restricts the JSC. The findings provide a substantial guidance on device optimization for Sb2S3 solar cells. [ABSTRACT FROM AUTHOR]

This article, titled "Methylammonium-Free Ink for Low-Temperature Crystallization of α-FAPbI3 Perovskite," was published in the journal Advanced Energy Materials. The authors, Tian Hou, Meng Zhang, Xiaoran Sun, Yihao Wang, Kaipeng Chen, Zhipeng Fu, Mingrui He, Xu Liu, Ziheng Liu, Yuelong Huang, Martin A. Green, and Xiaojing Hao, discuss a new method for fabricating α-FAPbI3 perovskite at low temperatures without the use of methylammonium (MA). The article includes an image illustrating the phase transition from hexagonal δ-FAPbI3 to cubic α-FAPbI3, and explains how the addition of PbCl2 and MPSO helps facilitate this transition. For more details, readers are directed to the full article. [Extracted from the article]