Structural modulation and assembling of metal halide perovskites for solar cells and light-emitting diodes

Funder: Singapore Economic Development BoardFunder: Energy Market Authority of Singapore; Id: http://dx.doi.org/10.13039/501100001447Funder: National Research Foundation Singapore; Id: http://dx.doi.org/10.13039/501100001381Funder: National University of Singapore; Id: http://dx.doi.org/10.13039/501100001352Funder: International Postdoctoral Exchange Fellowship Program (Talent‐Introduction Program) of ChinaFunder: Boya Postdoctoral program of Peking UniversityAbstract: Metal halide perovskites possess appealing optoelectronic properties and have been widely applied for solar energy harvesting and light emitting. Although perovskite solar cells (PeSCs) and perovskite light‐emitting diodes (PeLEDs) have been developed rapidly in recent years, there are still no universal rules for the selection of perovskites to achieve high‐performance optoelectronic devices. In this review, the working mechanisms of PeSCs and PeLEDs are first demonstrated with the discussion on the factors which determine the device performance. We then examine the optoelectronic properties of perovskites with structures modulated from 3D, 2D, 1D to 0D, and analyze the corresponding structure‐property relationships in terms of photo‐electric and electric‐photo conversion processes. Based on the unique optoelectronic properties of structurally modulated perovskites, we put forward the concept of structural assembling engineering that integrate the merits of different types of perovskites within one matrix and elaborate their excellent properties for applications of both PeSCs and PeLEDs. Finally, we discuss the potential challenges and provide our perspectives on the structural assembling engineering of perovskites for future optoelectronic applications. imag

A nine months follow-up study of hemodynamic effect on bioabsorbable coronary stent implantation

Coronary artery disease has emerged as one of the major diseases causing death worldwide. Coronary stent has great effect to improve blood flow to the myocardium subtended by that artery, in which bioresorbable vascular scaffolds are new-generation stents used by people. However, Coronary stents implantation has a risk of restenosis, which is relative to hemodynamic parameters. Most of existing literatures studied in this issue have not taken into account such important factors as the strut thickness and lumen profile, and has yet to analyze the time effects among hemodynamic parameters over a certain period of time based on individual models. In this research, we proposed a framework to assess the chronic impact of hemodynamic on coronary stent implantation. In the framework, the optical coherence tomography (OCT) is combined with angiography to reconstruct patient-specific models of bioresorbable vascular scaffolds. Then, the hemodynamics parameters are extracted through the simulated 3D models, obtaining the distribution of wall shear stress (WSS), relative residence time (RRT) and oscillatory shear index (OSI). Finally, the changes of these parameters representing the effectiveness of hemodynamics exerted on the implanted stent can be assessed to estimate the chronic impacts. By a 9-month follow-up case study, it is observed that the difference of hemodynamic parameters are not significance. Both at baseline and 9-month follow-up experiments show that the hemodynamic parameters remain normal and similar, proving that the coronary stent implantation nowadays appears to have a robust and everlasting curative effect

SERS of trititanate nanotubes : selective enhancement of catechol compounds

Funding: Xi'an Jiaotong Liverpool University. Grant Number: RDF- RDF-16-01-06.The surface enhanced Raman scattering of trititanate nanotubes (TiNT) modified with enediol ligands was investigated and it was found that the functional group dramatically affects the enhancement observed. For TiNT‐4‐nitrocatechol, a SERS enhancement is seen; however, when dopamine is attached, no signal is seen. The relative band gap positions upon 785 nm laser excitation are proposed to explain the observed phenomenon. This attachment is investigated by solid state NMR and UV/Vis spectroscopy and supported by DFT calculations to offers further insights into catechol coatings of nanomaterials and SERS by the chemical method. We expect this non noble metal containing composite material to have applications in bioimaging and bio and chemical detection.PostprintPeer reviewe

The antivirulence activity, transcriptomics of EGCG and its protective effects on zebrafish infected by Aeromonas hydrophila

BackgroundAeromonas hydrophila is an important pathogen that mainly harms aquatic animals and exhibits resistance to a variety of antibiotics. This study investigated the effect of epigallocatechin-3-gallate (EGCG) on the virulence factors of A.hydrophila and its impact on adhesion, invasion, and cytotoxicity in Caco-2 cells. The potential mechanism of antibacterial activity of EGCG was investigated by transcriptomic analysis.ResultsEGCG not only inhibited the production of biofilm, hemolytic activity, motility, and protease activity of A.hydrophila, but also reduced its adhesion, invasion, and cytotoxicity in Caco-2 cells. Transcriptomic analysis indicated that the antimicrobial activity of EGCG may be achieved by weakening the chemotaxis and stress response of the bacteria, as well as inhibiting the TonB system. Animal studies demonstrated that EGCG can significantly improve the survival rate and organs damage of zebrafish infected with A.hydrophila.ConclusionEGCG would be a potential alternative drug for the prevention and treatment of A. hydrophila infections by anti-virulence mechanism

SPEEK Membrane of Ultrahigh Stability Enhanced by Functionalized Carbon Nanotubes for Vanadium Redox Flow Battery

Proton exchange membrane is the key factor of vanadium redox flow battery (VRB) as their stability largely determine the lifetime of the VRB. In this study, a SPEEK/MWCNTs-OH composite membrane with ultrahigh stability is constructed by blending sulfonated poly(ether ether ketone) (SPEEK) with multi-walled carbon nanotubes toward VRB application. The carbon nanotubes disperse homogeneously in the SPEEK matrix with the assistance of hydroxyl group. The blended membrane exhibits 94.2 and 73.0% capacity retention after 100 and 500 cycles, respectively in a VRB single cell with coulombic efficiency of over 99.4% at 60 mA cm−2 indicating outstanding capability of reducing the permeability of vanadium ions and enhancing the transport of protons. The ultrahigh stability and low cost of the composite membrane make it a competent candidate for the next generation larger-scale vanadium redox flow battery

Roadmap on commercialization of metal halide perovskite photovoltaics

Perovskite solar cells (PSCs) represent one of the most promising emerging photovoltaic technologies due to their high power conversion efficiency. However, despite the huge progress made not only in terms of the efficiency achieved, but also fundamental understanding of the relevant physics of the devices and issues which affect their efficiency and stability, there are still unresolved problems and obstacles on the path toward commercialization of this promising technology. In this roadmap, we aim to provide a concise and up to date summary of outstanding issues and challenges, and the progress made toward addressing these issues. While the format of this article is not meant to be a comprehensive review of the topic, it provides a collection of the viewpoints of the experts in the field, which covers a broad range of topics related to PSC commercialization, including those relevant for manufacturing (scaling up, different types of devices), operation and stability (various factors), and environmental issues (in particular the use of lead). We hope that the article will provide a useful resource for researchers in the field and that it will facilitate discussions and move forward toward addressing the outstanding challenges in this fast-developing field

Cell transcriptomic atlas of the non-human primate Macaca fascicularis.

Studying tissue composition and function in non-human primates (NHPs) is crucial to understand the nature of our own species. Here we present a large-scale cell transcriptomic atlas that encompasses over 1 million cells from 45 tissues of the adult NHP Macaca fascicularis. This dataset provides a vast annotated resource to study a species phylogenetically close to humans. To demonstrate the utility of the atlas, we have reconstructed the cell-cell interaction networks that drive Wnt signalling across the body, mapped the distribution of receptors and co-receptors for viruses causing human infectious diseases, and intersected our data with human genetic disease orthologues to establish potential clinical associations. Our M. fascicularis cell atlas constitutes an essential reference for future studies in humans and NHPs.We thank W. Liu and L. Xu from the Huazhen Laboratory Animal Breeding Centre for helping in the collection of monkey tissues, D. Zhu and H. Li from the Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory) for technical help, G. Guo and H. Sun from Zhejiang University for providing HCL and MCA gene expression data matrices, G. Dong and C. Liu from BGI Research, and X. Zhang, P. Li and C. Qi from the Guangzhou Institutes of Biomedicine and Health for experimental advice or providing reagents. This work was supported by the Shenzhen Basic Research Project for Excellent Young Scholars (RCYX20200714114644191), Shenzhen Key Laboratory of Single-Cell Omics (ZDSYS20190902093613831), Shenzhen Bay Laboratory (SZBL2019062801012) and Guangdong Provincial Key Laboratory of Genome Read and Write (2017B030301011). In addition, L.L. was supported by the National Natural Science Foundation of China (31900466), Y. Hou was supported by the Natural Science Foundation of Guangdong Province (2018A030313379) and M.A.E. was supported by a Changbai Mountain Scholar award (419020201252), the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA16030502), a Chinese Academy of Sciences–Japan Society for the Promotion of Science joint research project (GJHZ2093), the National Natural Science Foundation of China (92068106, U20A2015) and the Guangdong Basic and Applied Basic Research Foundation (2021B1515120075). M.L. was supported by the National Key Research and Development Program of China (2021YFC2600200).S

Analytical Review of Spiro‐OMeTAD Hole Transport Materials: Paths Toward Stable and Efficient Perovskite Solar Cells

10.1002/aesr.202200045Advanced Energy and Sustainability Research2200045-220004