Topic Review
RMn2Hx Hydrides
Laves phases crystallize in simple structures and are very common intermetallic phases that can form from combinations of elements throughout the periodic table, giving a huge number of known examples. A special feature of AB2 or AB5 phases is the ability to absorb hydrogen.
  • 185
  • 07 Nov 2023
Topic Review
Angle-Resolved Photoemission Spectroscopy (ARPES)
Angle-resolved photoemission spectroscopy (ARPES) is a vital technique in which spectra are collected from both the energy and momentum of photoemitted electrons and is indispensable for investigating the electronic band structure of solids. 
  • 7.1K
  • 08 Dec 2020
Topic Review
Avalanche Photodiodes and Silicon Photomultipliers of Non-Planar Designs
Conventional designs of an avalanche photodiode (APD) have been based on a planar p–n junction since the 1960s. APD developments have been driven by the necessity to provide a uniform electric field over the active junction area and to prevent edge breakdown by special measures. Most modern silicon photomultipliers (SiPM) are designed as an array of Geiger-mode APD cells based on planar p–n junctions. Modern Silicon Photomultipliers (SiPM) are designed as an array of Geiger-mode APD cells based on planar p-n junctions. However, the planar design faces an inherent trade-off between photon detection efficiency and dynamic range due to loss of an active area at the cell edges. Non-planar designs of APDs and SiPMs have also been known since the development of spherical APD (1968), Metal-Resistor-Semiconductor APD (1989), and Micro-well APD (2005). Recent development of Tip Avalanche Photodiode (2020) based on the spherical p-n junction eliminates the trade-off, outperforms the planar SiPMs in the photon detection efficiency, and opens new opportunities for SiPM improvements. Moreover, the latest developments of APDs based on electric field-line crowding and charge-focusing topology with quasi-spherical p-n junctions (2019–2023) show promising functionality in linear and Geiger operating modes.
  • 531
  • 27 Jun 2023
Topic Review
Boron-Doped Diamond
Boron-doped diamond (BDD) acts as an excellent p-type conductive material for high-temperature, high-power and radiation-proof photoelectronic devices with its large band gap at room temperature (5.47 eV) and high thermal conductivity.
  • 2.3K
  • 06 Jan 2021
Topic Review
Bulk and Single Crystal Growth Progress of FBS
The new iron-based superconductor (FBS) has generated enormous interest in this direction, and many research activities are currently going on with various kinds of FBS. FBS was discovered in 2008 through F doped LaFeAsO, which crystallizes with a tetragonal layered ZrCuSiAs structure, and after that, many compounds have been discovered, most of which display superconductivity through suitable doping. FBS became the second high-Tc-superconducting family after cuprate superconductors and has been the subject of extensive research into their physical nature and application potential.
  • 605
  • 14 Jan 2022
Topic Review
Calculation of the transition temperature of superconducting elements
Using the Roeser-Huber formalism, we establish a non-trivial relation between the crystal structure and the transition temperature, Tc, to the superconducting state. By means of this relation, we can calculate Tc for practically all superconducting elements quite accurately within a small error margin. It is shown that this works well also for polymorphic elements and elements under pressure. Furthermore, the Roeser-Huber formalism implies that all calculated data fall on a common line with the slope m1 = h2/(2πkB) = 5.061 × 10−45 m2 kg K, when plotting log(Σ((2x)-2n1-1ML-1))-1 versus 1/Tc, which can be employed as a test when predicting Tc of unknown superconductors.
  • 856
  • 21 Jun 2023
Topic Review
Cellulose and Microfluidics
Cellulose, a linear polysaccharide, is the most common and renewable biopolymer in nature.
  • 917
  • 10 Feb 2022
Topic Review
Characterization of Ti/SnO2 Interface by X-ray Photoelectron Spectroscopy
The Ti/SnO2 interface has been investigated in situ via the technique of x-ray photoelectron spectroscopy. Thin films (in the range from 0.3 to 1.1 nm) of titanium were deposited on SnO2 substrates via the e-beam technique. The deposition was carried out at two different substrate temperatures, namely room temperature and 200 °C. The photoelectron spectra of tin and titanium in the samples were found to exhibit significant differences upon comparison with the corresponding elemental and the oxide spectra. These changes result from chemical interaction between SnO2 and the titanium overlayer at the interface. The SnO2 was observed to be reduced to elemental tin while the titanium overlayer was observed to become oxidized. Complete reduction of SnO2 to elemental tin did not occur even for the lowest thickness of the titanium overlayer. The interfaces in both the types of the samples were observed to consist of elemental Sn, SnO2, elemental titanium, TiO2, and Ti-suboxide. 
  • 520
  • 26 Jan 2022
Topic Review
Control and Upgradation of Indoor Air Quality
Due to increasing health and environmental issues, indoor air quality (IAQ) has garnered much research attention with regard to incorporating advanced clean air technologies. Various physicochemical air treatments have been used to monitor, control, and manage air contaminants, such as monitoring devices (gas sensors and internet of things-based systems), filtration (mechanical and electrical), adsorption, UV disinfection, UV photocatalysts, a non-thermal plasma approach, air conditioning systems, and green technologies (green plants and algae).
  • 605
  • 24 Feb 2023
Topic Review
Cryotropic Gelation and Macroporous Scaffolds
Cryogels obtained by the cryotropic gelation process are macroporous hydrogels with a well-developed system of interconnected pores and shape memory. Biodegradable cryogels have been prepared from natural polymers (biopolymers) and synthetic polymers with biodegradable/bioresponsive bonds containing bio-resembling or artificial units. The cryogels could be composed of one type of polymer or a combination of different materials. Polymers from natural origins (plants or animals) attract considerable attention for their intrinsic biocompatibility and potential ability to mimic ECM, favoring cell-matrix interactions for tissue-engineering and regeneration.
  • 1.2K
  • 12 Jul 2021
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