scholarly journals Low-Dimensional CsPbBr3@CoBr2 Super-Nanowire Structure for Perovskite/PMMA Composite with Highly Blue Emissive Performance

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1564
Author(s):  
Xuan-Viet Pham ◽  
Ba-Duc Tran ◽  
Duy-Cuong Nguyen ◽  
Tu Nguyen ◽  
Minh-Vuong Nguyen ◽  
...  
Keyword(s):  
Room Temperature ◽  
Carrier Lifetime ◽  
Electron Hole ◽  
One Pot ◽  
Transmission Electron ◽  
Electron Hole Pair ◽  
Low Dimensional ◽  
Color Rendering ◽  
Excellent Color ◽  
Nanowire Structure

In this study, low-dimensional CsPbBr3@CoBr2 super-nanowire (SNW) structures were synthesized via a one-pot heating strategy for highly blue emissions. By introducing CoBr2 to CsPbBr3 precursors, the shape of perovskite nanocrystals was changed from cuboids to a super-nanowire structure, as revealed through a transmission electron microscope. SNWs were formed from stacked segments of nano-plates (lateral dimension of 10–12 nm and thickness of ~2.5 nm) with lengths of several microns. The fabricated sample absorbs light at a wavelength of <450 nm, and it is emitted at a wavelength of 475 nm. It also has a radiant flux conversion efficiency of up to 85% when stimulated by a 430 nm LED light source. The average decay time of up to 80 µs indicates that they effectively prevent the recombination of electron–hole pair. The optical performance still remains over 65% when the ambient temperature is up to 120 °C compared with that under room temperature. The excellent color purity, optical quantum efficiency, long carrier lifetime, and thermal stability make CsPbBr3@CoBr2 SNWs highly promising for a range of photolumicescence applications, such as a high color rendering index lighting and transparent blue emissive screen.

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Hole Pair

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.

Donor-acceptor-like behavior of electron-hole pair recombinations in low-dimensional (Ga,In)N/GaN systems

2003 ◽  
Vol 68 (4) ◽  
Author(s):  
A. Morel ◽  
P. Lefebvre ◽  
S. Kalliakos ◽  
T. Taliercio ◽  
T. Bretagnon ◽  
...  
Keyword(s):  
Hole Pair ◽  
Electron Hole ◽  
Electron Hole Pair ◽  
Donor Acceptor ◽  
Low Dimensional

scholarly journals One-Pot Synthesis of Nitrogen-Doped TiO2 with Supported Copper Nanocrystalline for Photocatalytic Environment Purification under Household White LED Lamp

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6221
Author(s):  
Yixiao Pan ◽  
Yifei Wang ◽  
Shimiao Wu ◽  
Yating Chen ◽  
Xiangrong Zheng ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
White Led ◽  
Spectroscopy Analysis ◽  
Electron Hole ◽  
Absorption Properties ◽  
One Pot ◽  
Doped Tio2 ◽  
E Coli ◽  
Synthetic Strategy ◽  
Transmission Electron

Developing efficient and cheap photocatalysts that are sensitive to indoor light is promising for the practical application of photocatalysis technology. Here, N-doped TiO2 photocatalyst with loaded Cu crystalline cocatalyst is synthesized by a simple one-pot method. The structure is confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy analysis, which exhibit that Cu metal nanocrystalline is uniformly deposited on the surface of N-doped TiO2 material. UV-Vis absorption spectra illustrate that the modified samples possess favorable visible light absorption properties and suppressed-electron hole separation. The as-fabricated Cu-loaded N-TiO2 materials show high activity in photocatalytic decomposing isopropanol and inactivating E. coli under the irradiation of a household white LED lamp. The developed synthetic strategy and photocatalytic materials reported here are promising for indoor environment purification.

scholarly journals One pot synthesis of silver nanoparticles using a cyclodextrin containing polymer as reductant and stabilizer

2014 ◽  
Vol 5 ◽  
pp. 380-385 ◽  
Author(s):  
Arkadius Maciollek ◽  
Helmut Ritter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Optical Properties ◽  
Silver Nitrate ◽  
Room Temperature ◽  
One Pot ◽  
One Pot Synthesis ◽  
Transmission Electron ◽  
Vis Spectroscopy

A facile and one pot synthesis of silver nanoparticles with narrow size distributions using silver nitrate and a copolymer 1 from N-isopropylacrylamide (NIPAM) and mono-(1H-triazolylmethyl)-2-methylacryl-β-cyclodextrin acting as reductant and stabilizer without using any additional reducing agent is reported. The reduction was carried out in aqueous solution under pH neutral conditions at room temperature. The results of dynamic light scattering analysis and transmission electron microscopy show adjustable particle sizes from 30–100 nm, due to variation of silver nitrate concentration, the polymeric reducing and stabilisation agent concentration or reaction time. The spherical structure of the silver nanoparticles has been confirmed by UV–vis spectroscopy and transmission electron microscopy. The optical properties of the nanoparticles have also been characterized by fluorescence spectroscopy. The formed spherical particles are stable in aqueous medium at room temperature over a period of several weeks. Furthermore the changes in the optical properties of the nanoparticles due to thermo induced volume phase transition behavior of the thermoresponsive cyclodextrin containing polymer 1 have been characterized by UV–vis spectroscopy.

Magnetic Polyolefin-based Nanocomposites

2013 ◽  
Vol 1499 ◽  
Author(s):  
Qingliang He ◽  
Suying Wei ◽  
Zhanhu Guo
Keyword(s):  
Thermal Decomposition ◽  
Magnetic Nanoparticles ◽  
Room Temperature ◽  
Magnetic Particles ◽  
Formation Mechanisms ◽  
Gravimetric Analysis ◽  
One Pot ◽  
Metallic Precursor ◽  
Transmission Electron

ABSTRACTMagnetic polyolefin-based nanocomposites were fabricated through a facile one-pot thermal decomposition of organo-metallic precursor, i.e. Fe(CO)5 in polymer-solvent solution condition. The whole fabrication includes dissolution of polyolefin-based hosting matrix in refluxing organic solvent followed by the injection of metallic precursor to perform the in-situ thermal decomposition step. The particle sizes, morphology and dispersion quality of these in-situ synthesized magnetic nanoparticles were investigated by transmission electron microscopy (TEM). Room temperature mössbauer spectrum analysis was used to determine the species of these magnetic nanoparticles. Room temperature magnetic property investigation was utilized to further reveal the magnetic behaviors of these nanocomposites by specifying the saturation magnetization and coercive forces. Thermal gravimetric analysis (TGA) was used to determine the thermal stability of these as-prepared nanocomposites and the particle loadings. The formation mechanisms of these magnetic particles were proposed from the evidence of TEM observations and detailed evolutions are detailed as well.

Hydrogen Collision Model of The Staebler-Wronski Effect: Microscopics and Kinetics

1998 ◽  
Vol 507 ◽  
Author(s):  
Howard M. Branz
Keyword(s):  
Room Temperature ◽  
Pair Creation ◽  
Hole Pair ◽  
Dangling Bond ◽  
Electron Hole ◽  
Spin Resonance ◽  
Electron Hole Pair ◽  
Staebler Wronski Effect ◽  
Hydrogenated Amorphous ◽  
Creation Rate

ABSTRACTA new microscopic and kinetic model of light-induced metastability in hydrogenated amorphous silicon (a-Si:H) is described. Recombination and trapping of photoinduced carriers excite hydrogen from deep Si-H bonds into a mobile configuration, leaving a dangling bond (DB) defect at the site of excitation. Normally, mobile H are recaptured at DB defects and no metastability or net DB production results. However, when two mobile H collide, they form a metastable two-hydrogen complex and leave two spatially-uncorrelated Staebler-Wronski DBs. Thermal and light-induced annealing occur when mobile H are excited from the metastable two-H complex; they diffuse and are recaptured to DBs. The microscopic model is entirely compatible with electron-spin-resonance results showing neither DB-DB nor DB-H spatial correlation of the light-induced DBs. The model leads to new differential equations describing the evolution of the mobile H and DB densities. These equation equations explain the observed room-temperature Ndb∼G2/3t1/3 dependence of DB creation upon the electron-hole pair creation rate (G) and time. The model also accounts for both t1/3-kinetics at 4.2K and t1/2-kinetics under laser-pulse soaking. Neither of these results can be explained within the prevailing electron-hole pair recombination model.

CMOS compatible Si/SiO2 multilayers for Light Emitting Diodes

2000 ◽  
Vol 638 ◽  
Author(s):  
Z. Gaburro ◽  
L. Pavesi ◽  
G. Pucker ◽  
P. Bellutti
Keyword(s):  
Quantum Confinement ◽  
Room Temperature ◽  
Blackbody Radiation ◽  
Single Type ◽  
Hot Electron ◽  
Electron Hole ◽  
Light Emitting ◽  
Electron Relaxation ◽  
Electron Hole Pair ◽  
Plasmon Polaritons

AbstractWe report photoluminescence and electroluminescence at room temperature in diodes based on Si/SiO2 multilayers. The multilayers are fabricated by alternating Si and SiO2 layers, whose thickness is, respectively, 2 and 5 nanometers. In photoluminescence, a single band is observed, centered at 800 nm, which is due to electron-hole pair recombination under quantum confinement. On the other hand, in electroluminescence, two bands are reported. The first band is in the infrared spectrum, and is blackbody radiation. The second band is visible, and is originated by relaxation of a single type of electrical carrier (electrons), as suggested by a fast decay time (less than 0.1 µs). Possible mechanisms can be hot-electron relaxation or coupling with surface plasmon-polaritons.

The Doping and Characterization of Erbium-Implanted Gan

1997 ◽  
Vol 482 ◽  
Author(s):  
J. T. Torvik ◽  
R. J. Feuerstein ◽  
C. H. Qiu ◽  
J. I. Pankove ◽  
F. Namavar
Keyword(s):  
Room Temperature ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Device Performance ◽  
Hot Electron ◽  
Electron Hole ◽  
Excitation Process ◽  
Electron Hole Pair ◽  
Single Exponential

AbstractStrong room temperature Er-related photoluminescence (PL) and electroluminescence (EL) at 1539 nm was observed from Er and 0 implanted n-type GaN. Good device performance requires that the Er-related excitation and emission processes be efficient. Single exponential PL and EL time decays with l/e lifetimes of 2.33 ms and 1.74 ms indicates highly efficient radiative process. The Er excitation process in GaN was studied by comparing the efficiency of direct Erabsorption, electron-hole pair recombination, and hot electron (impact) excitation. The strongest Er luminescence and the lowest pump power was found using impact excitation.

Crystal growth of photovoltaic polycrystalline Si1-xGex by die-casting growth

2004 ◽  
Vol 836 ◽  
Author(s):  
H. Hirahara ◽  
T. Iida ◽  
Y. Sugiyama ◽  
T. Baba ◽  
Y. Takanashi ◽  
...  
Keyword(s):  
Room Temperature ◽  
Die Casting ◽  
Band Gap Energy ◽  
Optical Absorption Coefficient ◽  
Electron Hole ◽  
Electron Hole Pair ◽  
Complete Series ◽  
Indirect Band Gap ◽  
Growth Methods ◽  
Room Temperature Optical Absorption

ABSTRACTCoin-shaped multicrystalline Si1-xGex crystals were grown using a Brigdman method combined with die-casting growth. Si1-xGex alloy is known as a candidate material for producing Auger generation, which creates more than one electron/hole pair per absorbed photon. Since Si1-xGex alloy shows a complete series of solid solutions, precipitating crystals with a certain composition of silicon or germanium by conventional selective growth methods is burdensome. Using die-casting combined with Bridgman growth brought about Si1-xGex precipitation in a form completely different from that predicted by the Si-Ge phase diagram. By combining this growth with subsequent heat treatment of the precipitated Si1-xGex sample, Si1-xGex (x= 0.5 ± 3 %) could be obtained. Indirect band-gap energy was estimated by measuring room-temperature optical absorption coefficient of the grown samples.

Sign in / Sign up

Export Citation Format

Share Document