Search results for " Wells"

MR3063436 Reviewed Znojil, Miloslav; Wu, Junde A generalized family of discrete PT-symmetric square wells. Internat. J. Theoret. Phys. 52 (2013), no.…

2014

Consequences of the spatial localization on the exciton recombination dynamics in InGaP/GaAs heterostructures

2002

5 páginas, 4 figuras.

Study of the photocatalytic activity of Keggin and Wells Dawson heteropolyacids: role of the acidity and of the pseudo-liquid phase regime

2017

Study of the photocatalytic activity of Keggin and Wells Dawson heteropolyacids: role of the acidity and of the pseudo-liquid phase regime

Blue lasing at room temperature in high quality factor GaN/AlInN microdisks with InGaN quantum wells

2007

The authors report on the achievement of optically pumped III-V nitride blue microdisk lasers operating at room temperature. Controlled wet chemical etching of an AlInN interlayer lattice matched to GaN allows forming inverted cone pedestals. Whispering gallery modes are observed in the photoluminescence spectra of InGaN/GaN quantum wells embedded in the GaN microdisks. Typical quality factors of several thousands are found (Q>4000). Laser action at similar to 420 nm is achieved under pulsed excitation at room temperature for a peak power density of 400 kW/cm(2). The lasing emission linewidth is down to 0.033 nm.

Wells futurologo

2021

Una lettura critica del saggio di H.G Wells "La scoperta del futuro" con cui l'autore di letteratura di fantascienza definisce i caratteri di una nuova disciplina che alcuni decenni più tardi si sarebbe chiamata Futurologia. A critical reading of the essay by H.G Wells "The discovery of the future" with which the author of science fiction literature defines the characteristics of a new discipline that a few decades later would be called Futurology.

Indium surfactant effect on AlN/GaN heterostructures grown by metal-organic vapor-phase epitaxy: Applications to intersubband transitions

2006

We report on a dramatic improvement of the optical and structural properties of AlN/GaN multiple quantum wells (MQWs) grown by metal-organic vapor-phase epitaxy using indium as a surfactant. This improvement is observed using photoluminescence as well as x-ray diffraction. Atomic force microscopy shows different surface morphologies between samples grown with and without In. This is ascribed to a modified relaxation mechanism induced by different surface kinetics. These improved MQWs exhibit intersubband absorption at short wavelength (2 mu m). The absorption linewidth is as low as 65 meV and the absorption coefficient is increased by 85%.

Intense laser effects on donor impurity in a cylindrical single and vertically coupled quantum dots under combined effects of hydrostatic pressure an…

2010

WOS: 000280235800010

Correlation between optical properties and barrier composition in InxGa1−xP/GaAs quantum wells

1998

9 páginas, 11 figuras.

Considerations on sand control in natural gas wells

2017

Mechanism of sand production in gas wells is complex and influenced by every operation performed into the well, starting from the opening of the production interval by drilling, and continuing with completion and putting into production as well as with the exploitation regime. Sand production along with fluids from gas reservoirs creates a series of potentially dangerous and costly problems. For selecting the most appropriate methods of sand-control all the data and information related to properties of reservoir rock, the history of sand production, the potential well flow rates as well as HSE and costs need to be evaluated. The conclusion of the authors is that the best results in sand con…

Effects of rapid thermal annealing on the optical properties of low-loss 1.3μm GaInNAs∕GaAs saturable Bragg reflectors

2004

We report studies of the effect of rapid thermal annealing (RTA) on the optical properties of a low-loss 1.3 mum saturable Bragg reflector (SBR), consisting of a GaInNAs/GaAs single quantum well embedded in an AlAs/GaAs Bragg reflector grown monolithically on a GaAs substrate. RTA gives rise to a blueshift of the photoluminescence (PL) peak (and therefore of the excitonic absorption peak) and an enhancement of PL intensity, while the reflectivity properties including peak reflectivity and bandwidth are not degraded. Temperature dependent photoluminescence measurements show that the RTA-induced blueshift of photoluminescence consists of two components: one originating from the increase of op…