Use of Recycling-Reflection Color-Purity Enhancement Film to Improve Color Purity of Full-Color Micro-LEDs

A common full-color method involves combining micro-light-emitting diodes (LEDs) chips with color conversion materials such as quantum dots (QDs) to achieve full color. However, during color conversion between micro-LEDs and QDs, QDs cannot completely absorb incident wavelengths cause the emission wavelengths that including incident wavelengths and converted wavelength through QDs, which compromises color purity. The present paper proposes the use of a recycling-reflection color-purity-enhancement film (RCPEF) to reflect the incident wavelength multiple times and, consequently, prevent wavelength mixing after QDs conversion. This RCPEF only allows the light of a specific wavelength to pass through it, exciting blue light is reflected back to the red and green QDs layer. The prototype experiment indicated that with an excitation light source wavelength of 445.5 nm, the use of green QDs and RCPEFs increased color purity from 77.2% to 97.49% and light conversion efficiency by 1.97 times and the use of red QDs and RCPEFs increased color purity to 94.68% and light conversion efficiency by 1.46 times. Thus, high efficiency and color purity were achieved for micro-LEDs displays. Graphical Abstract

Modern Electromobility and the Possibility of How to Achieve a Higher Capacity of the Li-ion Batteries

This article is describing the evolution of modern electromobilitywith describing the problematics connected with the shape of cells in battery modules. There are mentioned Li-ion battery's anode materials with their basic parameters and one of the conversion materials, silicon, which looks like promising material for future enhancing anode capacity. Usage of this material brings some new challenges, which prevents use in practice and must be solved. One of these solutions can be by applying external pressure, which can, for example, improve internal conductivity

SYNTHESIS AND APPLICATION OF CNT BASED ENERGY STORAGE AND CONVERSION DEVICES

Carbon nanotubes (CNTs) are one-dimensional tubular structures of carbon that have attracted much attention due to their potential to be used in various fields like energy storage/conversion devices, biosensing devices, drug delivery systems to name a few. Their excellent electrochemical properties like electron mobility, electrical and thermal conductivity, and high surface area make them good material for use in energy storage and conversion materials. The most promising research in the synthesis and applications of CNTs toward energy conversion and storage is highlighted along with limitations faced in mass production.

SYNTHESIS AND APPLICATION OF CNT BASED ENERGY STORAGE AND CONVERSION DEVICES

Carbon nanotubes (CNTs) are one-dimensional tubular structures of carbon that have attracted much attention due to their potential to be used in various fields like energy storage/conversion devices, biosensing devices, drug delivery systems to name a few. Their excellent electrochemical properties like electron mobility, electrical and thermal conductivity, and high surface area make them good material for use in energy storage and conversion materials. The most promising research in the synthesis and applications of CNTs toward energy conversion and storage is highlighted along with limitations faced in mass production.

Synthesis Techniques for rare Earth doped up-conversion Nano-materials for Solar cells – A brief Review

Extended efficiency of solar cells to ensemble more solar energy as well as its optimum conversion and utilization is believed to be a major challenge in current times. The spectral mismatch between the distribution of energy in the solar spectrum incidence and the semiconducting material band gap is a major restriction in the performance of solar cells. The conversion of wavelength of the sun is a necessary requisite to reduce spectral disruption. Of late, the solar cell converters are presumed as up-converted components and products derived from down conversion. Materials like NaCsWO3, NaYF4, and NaYF4: Yb, Er are synthesized and used to overcome the problem like deficiency of up-conversion luminescence (UCL) materials and device structures. The intensity of UCL can be enhanced by a significant time when the amount of NaCsWO3 is 2.8 m mol per cent. UCL material is considered as one of the best approaches to obtain high-efficiency perovskite solar cells (PSCs). In order to overcome these difficulties, not only were these effective up-conversion nano-particles (UPCNPs) doped into the hole layer but the perovskite foil was also modified in PSCs. The highest power conversion (PCE) performance reached 18.89%. Enhanced UCLs allow for UCNPs to extend the recognition spectrum of near PSCs. The objective of this comprehensive and focused review is to highlight the different synthesis techniques used in up-conversion nano-materials, for solar cell applications along with a theoretical perspective in this regard.

Applications of Density Functional Theory on Heavy Metal Sensor and Hydrogen Evolution Reaction (HER)

A great effort has been devoted to develop the numerical methods to solve Schrödinger equation for atoms and molecules which help to reveal the physico-chemical process and properties of various known/unknown materials. Designing the efficient probe to sense the heavy metals is a crucial process in chemistry. And, during this energy crisis, to find the effective conversion materials for water splitting is an important approach. The density functional theory (DFT) is a powerful tool to identify such materials and made great achievements in the field of heavy metal chemosensor and photocatalysis. Particularly, DFT helps to design the chemosensor for the effective sensor applications. The universe is moving towards the exhaustion of fossil fuels in a decade and so on, DFT plays a vital role to find the green energetic alternative to fossil fuel which is the Hydrogen energy. This book chapter will focus on the application of DFT deliberately on the heavy metal sensors and hydrogen evolution reaction.

Liquid intrusion in and extrusion from non-wettable nanopores for technological applications

In this article, we review some recent theoretical results about intrusion and extrusion of non-wetting liquids in and out of cavities of nanotextured surfaces and nanoporous materials. Nanoscale confinement allows these processes to happen at conditions which significantly differ from bulk phase coexistence. In particular, the pressure at which a liquid penetrates in and exits from cavities is of interest for many technological applications such as energy storage, dissipation, and conversion, materials with negative compressibility, ion channels, liquid chromatography, and more. Notwithstanding its technological interest, intrusion/extrusion processes are difficult to understand and control solely via experiments: the missing step is often a simple theory capable of providing a microscopic interpretation of the results, e.g., of liquid porosimetry or other techniques used in the field, especially in the case of complex nanoporous media. In this context, simulations can help shedding light on the relation between the morphology of pores, the chemical composition of the solids and liquids, and the thermodynamics and kinetics of intrusion and extrusion. Indeed, the intrusion/extrusion kinetics is determined by the presence of free energy barriers and special approaches, the so-called rare event techniques, must be used to study these processes. Usually, rare event techniques are employed to investigate processes occurring in relatively simple molecular systems, while intrusion/extrusion concerns the collective dynamics of hundreds to thousands of degrees of freedom, the molecules of a liquid entering in or exiting from a cavity, which, from the methodological point of view, is itself a challenge.