Optical properties of core/shell spherical quantum dots*

Abstract

In this study, the effects of quantum dot size on the binding energy, radiative lifetime, and optical absorption coefficient of exciton state in both GaN/Al x Ga1−x N core/shell and Al x Ga1−x N/GaN inverted core/shell quantum dot structures are studied. For the GaN/Al x Ga1−x N core/shell structure, the variation trend of binding energy is the same as that of radiation lifetime, both of which increase first and then decrease with the increase of core size. For Al x Ga1−x N/GaN inverted core/shell structure, the binding energy decreases first and then increases with core size increasing, and the trends of radiation lifetime varying with core size under different shell sizes are different. For both structures, when the photon energy is approximately equal to the binding energy, the peak value of the absorption coefficient appears, and there will be different peak shifts under different conditions.

Majorana fermions induced fast- and slow-light in a hybrid semiconducting nanowire/superconductor device

“…[17] In order to observe Majorana-like signatures, several significant experimental schemes have been proposed, including the zerobias peaks (ZBPs) in tunneling spectroscopy, [9][10][11][12][13] the Josephson effect, [18] the Coulomb blockade spectroscopy, [15] and the spin-resolved measurements. [19] On the other hand, due to the significant progress in modern nanoscience and nanotechnology, artificial atoms, i.e., quantum dots (QDs), [20][21][22][23][24][25] manifest the attractive intermediary for probing MFs both theoretically [26][27][28][29][30] and experimentally. [31] However, in the detection of MFs with QDs in the electrical domain, QDs are always considered as only a resonant level.…”

Zebrafish imaging and two-photon fluorescence imaging using ZnSe quantum dots*

“…Semiconductor quantum dots (QDs) have attracted much attention in recent years due to their unique optical properties. [1][2][3] The QDs have good chemical stability and can adapt to environments with large variations in pH range. [4] By adjusting their composition and size, QDs can emit the lights with various colors to supplement the green autofluorescence of living organisms.…”

Anisotropic exciton Stark shift in hemispherical quantum dots

“…[1][2][3][4][5][6][7] With nanostructure sizes decreasing, the geometrical shapes of nanostructures become more and more important because they significantly modify the electronic structures and modulate other physical properties. [8][9][10] Since the spherical symmetry is broken, HQDs are able to control many properties of macroscopic materials by means of quantum-mechanical effects. They provide a threedimensional carrier confinement resulting in the superior carrier localization and optical confinement capabilities.…”