Dielectric capacitors with the prominent features of ultrafast charging-discharging rates and ultrahigh power densities are ubiquitous components in modern electronics. To meet the growing demand for ...electronics miniaturization, dielectric capacitors with high energy storage properties are extensively researched. Here we present an overview of the recent progress in the engineering of multiscale structures of dielectric ceramics ranging from bulk to thin films. This article commences with a brief introduction of the fundamentals of dielectric ceramics, including primary parameters, a library of dielectric ceramics, and multiscale structures. Emphases are placed on the relationship between multiscale structures and energy storage properties and the rational structure design principles in dielectric ceramics. Also included are currently available multilayer ceramic capacitors based on multiscale engineered ceramic structures. Finally, challenges along with opportunities for further research and development of high-performance dielectric ceramics for electrostatic energy storage are highlighted.
An overview of the recent progress in the engineering of multiscale structures of dielectric ceramics for electrostatic energy storage applications is presented.
A substantial proportion of liver cancers is attributable to chronic infection with hepatitis B and C (HBV/HCV). Liver cancer could become the second cancer, after cervical, to be effectively ...controlled globally, if proven interventions such as vaccination can be implemented on a large scale. In 2018, the global mortality rate for liver cancer was estimated to be 8.5 per 100 000 individuals. Given patterns of HBV infection and immigration across countries, liver cancer control requires combined, global action. Liver cancer trends vary between countries, in some Western countries, the incidence rates were relatively low but have increased in recent decades; conversely, in several Asian countries, the incidence rates have decreased over time. China has in the past contributed more than half of the global burden of liver cancer but more recently a national decline in liver cancer incidence has been observed. Here, we review the liver cancer burden and exposure to risk factors in China, compared to other countries. We also review the implementation status for primary and secondary prevention interventions and major outcomes achieved over the past three decades. Using Bayesian age‐period‐cohort analysis, we examine recent trends and based on these, predict that by 2050, the incidence of liver cancer in China could fall by half. We additionally survey the literature to identify current research needs, and review relevant national policies on liver cancer control in China. A comprehensive set of interventions is proposed to progress toward the long‐term goal of liver cancer elimination based on the natural history and evidence‐based interventions.
Environment‐friendly lead‐free piezoelectric ceramics have been studied extensively in the past decade with great progress particularly in systems based on a niobate perovskite compound formulated as ...(K, Na)NbO3 (abbreviated as KNN). A comprehensive review on the latest development of KNN‐based piezoelectric ceramics is presented in this article, including the phase structure, property enhancement approaches, and sintering processes as well as the status of some promising applications. The phase structure of KNN was reexamined and associated with the effect of chemical modification on its tetragonal‐to‐orthorhombic transition. Then, a special focus is placed on the temperature dependence of piezoelectric properties of KNN‐based ceramics, followed by reviewing the recent approaches devoted to the temperature‐stability enhancement. The processing fundamentals related to the sintering of KNN‐based ceramics are also presented with an emphasis on compositional and microstructural control. Finally, this review introduces several industrial attempts of traditional piezoceramic products using KNN‐based ceramics and the studies on some promising application in authors' laboratory.
In this work, significant suppression of the interfacial recombination by facile alkali chloride interface modification of the NiOx hole transport layer in inverted planar perovskite solar cells is ...achieved. Experimental and theoretical results reveal that the alkali chloride interface modification results in improved ordering of the perovskite films, which in turn reduces defect/trap density, causing reduced interfacial recombination. This leads to a significant improvement in the open‐circuit voltage from 1.07 eV for pristine NiOx to 1.15 eV for KCl‐treated NiOx, resulting in a power conversion efficiency approaching 21%. Furthermore, the suppression of the ion diffusion in the devices is observed, as evidenced by stable photoluminescence (PL) under illumination and high PL quantum efficiency with alkali chloride treatment, as opposed to the luminescence enhancement and low PL quantum efficiency observed for perovskite on pristine NiOx. The suppressed ion diffusion is also consistent with improved stability of the devices with KCl‐treated NiOx. Thus, it is demonstrated that a simple interfacial modification is an effective method to not only suppress interfacial recombination but also to suppress ion migration in the layers deposited on the modified interface due to improved interface ordering and reduced defect density.
Suppression of the interfacial recombination are achieved by facile alkali chloride modification of the nickel oxide in inverted perovskite solar cells. It is demonstrated that the interface modification induces the ordering of the perovskite crystal at the interfaces, which in turn reduces defect/trap density, causing reduced interfacial recombination. This results in dramatically improvement of the open circuit voltage and power conversion efficiency.
Organic–inorganic hybrid perovskite solar cells have resulted in tremendous interest in developing next generation photovoltaics due to high record efficiency exceeding 22%. For inverted structure ...perovskite solar cells, the hole extraction layers play a significant role in achieving efficient and stable perovskite solar cell by modifying charge extraction, interfacial recombination losses, and band alignment. Here, cesium doped NiOx is selected as a hole extraction layer to study the impact of Cs dopant on the optoelectronic properties of NiOx and the photovoltaic performance. Cs doped NiOx films are prepared by a simple solution‐based method. Both doped and undoped NiOx films are smooth and highly transparent, while the Cs doped NiOx exhibits better electron conductivity and higher work function. Therefore, Cs doping results in a significant improvement in the performance of NiOx‐based inverted planar perovskite solar cells. The best efficiency of Cs doped NiOx devices is 19.35%, and those devices show high stability as well. The improved efficiency in devices with Cs:NiOx is attributed to a significant improvement in the hole extraction and better band alignment compared to undoped NiOx. This work reveals that Cs doped NiOx is very promising hole extraction material for high and stable inverted perovskite solar cells.
Cesium doping of NiOx enhances the conductivity of the oxide film and the hole extraction from the perovskite film in inverted planar perovskite solar cells. Significantly improved photovoltaic performance is obtained with the best efficiencies of 16.04% and 19.35% for NiOx and Cs:NiOx, respectively. The devices exhibit negligible hysteresis and good stability.
ABSTRACT Water, energy and food (WEF) are important strategic resources for economic development in arid agriculture-based regions. Analyzing development indicators in the management of limited ...resources to achieve sustainability on a time scale is one of the basic goals of this research. Therefore, a system dynamics model was developed to analyze the WEF system resource flow relationship to achieve sustainable resource development. First, the subsystems of WEF resources were created and their dynamic relationship was formed in the form of a logical loop in a 10-year time frame. The evolution of 7 years (from 2015 to 2022) was taken into consideration to predict the 3-year period (from 2023 to 2025). The results showed that the reduction of water resources exploitation rate in China in interaction with agricultural productivity has automatically improved energy consumption and the nexus index. In China, a dynamic balance between WEF with a focus on water is recommended for planning.
The demand for high-temperature dielectric materials arises from numerous emerging applications such as electric vehicles, wind generators, solar converters, aerospace power conditioning, and ...downhole oil and gas explorations, in which the power systems and electronic devices have to operate at elevated temperatures. This article presents an overview of recent progress in the field of nanostructured dielectric materials targeted for high-temperature capacitive energy storage applications. Polymers, polymer nanocomposites, and bulk ceramics and thin films are the focus of the materials reviewed. Both commercial products and the latest research results are covered. While general design considerations are briefly discussed, emphasis is placed on material specifications oriented toward the intended high-temperature applications, such as dielectric properties, temperature stability, energy density, and charge-discharge efficiency. The advantages and shortcomings of the existing dielectric materials are identified. Challenges along with future research opportunities are highlighted at the end of this review.
Plasmonic color filtering and color printing have attracted considerable attention in recent years due to their supreme performance in display and imaging technologies. Although various color‐related ...devices are designed, so far very few studies have touched the topic of dynamic color generation. In this article, dynamic color generation is demonstrated by integrating plasmonic nanostructures with vanadium dioxide based on its tunable optical properties through insulator–metal transition. Periodic arrays of silver nanodisks on a vanadium dioxide film are fabricated to realize different colors, relying on the excitation of localized and propagating surface plasmons, and Wood's anomaly. By tuning spatial periodicity of the arrays and diameter of the silver nanodisks, various colors can be achieved across the entire visible spectrum. Further, using insulator–metal transition of vanadium dioxide, the colors can be actively tuned by varying temperature. The approach of dynamic color generation based on the phase transition of vanadium dioxide can easily realize diverse color patterns, which makes it beneficial for display and imaging technology with distinct advantages of multifunctionality, flexibility, and high efficiency.
Dynamic color generation is realized by integrating plasmonic nanostructures with vanadium dioxide based on its tunable optical properties through insulator–metal transition. Various colors can be designed across the visible spectrum via adjusting the spatial periodicity and nanodisk diameter of the silver‐nanodisk array, and the colors can be tuned dynamically by varying the temperature.
Lead‐free dielectric ceramics have been the spotlight in the search for environmentally benign materials for electrostatic energy storage because of the ever‐increasing environmental concerns. ...However, the inverse correlation between the polarization and dielectric breakdown strength is the major barrier hindering the provision of sufficient energy densities in lead‐free dielectric ceramics and practical applications thereof. Herein, a rational structure design inspired by nature is demonstrated as an effective strategy to overcome these challenges. Bioinspired raspberry‐like hierarchically structured all‐inorganic nanocomposites have been prepared by enclosing microsized BaTiO3‐Bi(Mg0.5Zr0.5)O3 (BT‐BMZ) relaxor ferroelectrics using core‐shell BT‐BMZ@SiO2 nanoparticles. The synergistic effects of the bioinspired hierarchical structure and insulating SiO2 nano‐coating result in significantly improved dielectric breakdown strength and sustained large polarization in the nanocomposites, as corroborated by experimental characterizations and theoretical simulations. As a result, an ultrahigh energy density of 3.41 J cm−3 and a high efficiency of 85.1%, together with outstanding thermal stability within a broad temperature range, have been simultaneously achieved in the hierarchically structured nanocomposites. This contribution provides a feasible and paradigmatic approach to develop high‐performance dielectrics for electrostatic energy storage applications using bioinspired structure design.
A conceptual material paradigm of structure design strategy inspired by nature is developed to break the inverse correlation between polarization and breakdown strength inherently existing in dielectrics, and thus to boost their energy storage performance, as successfully validated by the bioinspired hierarchical structured all‐inorganic BaTiO3‐Bi(Mg0.5Zr0.5)O3‐based nanocomposites with a high energy density of 3.41 J cm−3, and efficiency of 85.1% simultaneously.
Grain boundaries in lead halide perovskite films lead to increased recombination losses and decreased device stability under illumination due to defect‐mediated ion migration. The effect of a ...conjugated polymer additive, poly(bithiophene imide) (PBTI), is investigated in the antisolvent treatment step in the perovskite film deposition by comprehensive characterization of perovskite film properties and the performance of inverted planar perovskite solar cells (PSCs). PBTI is found to be incorporated within grain boundaries, which results in an improvement in perovskite film crystallinity and reduced defects. The successful defect passivation by PBTI yields reduces recombination losses and consequently increases power conversion efficiency (PCE). In addition, it gives rise to improved photoluminescence stability and improved PSC stability under illumination which can be attributed to reduced ion migration. The optimal devices exhibit a PCE of 20.67% compared to 18.89% of control devices without PBTI, while they retain over 70% of the initial efficiency after 600 h under 1 sun illumination compared to 56% for the control devices.
A semiconducting conjugated polymer, poly(bithiophene imide), is successfully introduced to perovskite grain boundaries along with augmented grain sizes. This results in effective defect passivation and hence reduced recombination losses and increased efficiency, as well as reduced ion migration and improved stability.
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