Related papers: Stark effect, polarizability and electroabsorption…
The ground state and the dielectric response of stacked quantum rings are investigated in the presence of an applied magnetic field along the ring axis. For odd number $N$ of rings and an electric field perpendicular to the axis, a linear…
Current-voltage measurements have been made at room temperature on a Si-rich silicon oxide film deposited via Electron-Cyclotron Resonance Plasma Enhanced Chemical Vapor Deposition (ECR-PECVD) and annealed at 750 - 1000$ ^\circ$C. The…
Crystalline Silicon-on-Sapphire (SOS) films were implanted with boron (B$^+$) and phosphorous (P$^+$) ions. Different samples, prepared by varying the ion dose in the range $10^{14}$ to 5 x $10^{15}$ and ion energy in the range 150-350 keV,…
Spin properties of two interacting electrons in a quantum dot (QD) embedded in a nanowire with controlled aspect ratio and longitudinal magnetic fields are investigated by using a configuration interaction (CI) method and exact…
Accurate energy-size dependence of excitonic transitions in semiconductor nanocrystals in the strong confinement regime using classical theoretical approaches such as effective mass approximation, tight binding, or empirical…
In an effort to elucidate the spin (rather than charge) degrees of freedom in colloidal semiconductor nanocrystal quantum dots, we report on a series of static and time-resolved photoluminescence measurements of colloidal CdSe quantum dots…
We report on simulations and measurements of the optical absorption of silicon nanowires (NWs) versus their diameter. We first address the simulation of the optical absorption based on two different theoretical methods : the first one,…
The exciton states of strained CdTe/CdS core-shell tetrapod-shaped nanocrystals were theoretically investigated by the numerical diagonalization of a configuration interaction Hamiltonian based on the single-band effective mass…
Coupled electron-nuclear spins represent a promising quantum system, where the optically induced electron spin polarization can be dynamically transferred to nuclear spins via the hyperfine interaction. Most experiments on dynamic nuclear…
We report on the possibility of describing the absorption and emission characteristics of an ensemble of silicon nanocrystals (NCs) with realistic distributions in the NC size, by the sum of the reponses of the single NCs. The individual NC…
The absorption and emission spectra of silicon nanocrystals up to 1 nm diameter including geometry optimization and the many-body effects induced by the creation of an electron-hole pair have been calculated within a first-principles…
Large surface to volume ratios of semiconductor nanocrystals cause susceptibility to charge trapping, which can modify luminescence yields and induce single-particle blinking. Optical spectroscopies cannot differentiate between bulk and…
Quantum confinement is the discretization of energy when motion of particles is restricted to length scales smaller than their de Broglie wavelength. The experimental realization of this effect has had wide ranging impact in diverse fields…
We report the observation of carrier mediated decrease in the stiffness of crystalline (c)-Si(100) under nanoindentation. The apparent elastic modulii of heavily dopes (1E21 cm-3) p- and n-type c-Si are observed to be lower by 5.-7.5…
Solid-state refrigeration technology based on caloric effects are promising to replace the currently used vapor compression cycles. However, their application is restricted due to limited performances of caloric materials. Here, we have…
A spherical quantum dot (QD) heterosystem CdS/SiO$_2$ has been studied. Each QD has a hydrogen-like impurity in its center. Besides that, it has been accounted that a polarization trap for electron exists at the interfaces due to the…
Luminescence and optical absorption due to radiation damage centers in silicon has been studied exhaustively for decades, but is receiving new interest for applications as emitters for integrated silicon photonic technologies. While a…
The energy levels and optical transitions of tetrahedral core/shell InP/ZnSe quantum dots (QDs) are investigated by means of multi-band k$\cdot$p theory. Despite the $\overline{T}_d$ symmetry relaxing spherical selection rules, the…
All electronic, optoelectronic or photovoltaic applications of silicon depend on controlling majority charge carriers via doping with impurity atoms. Nanoscale silicon is omnipresent in fundamental research (quantum dots, nanowires) but…
The structure of the electron quantum size levels in spherical nanocrystals is studied in the framework of an eight--band effective mass model at zero and weak magnetic fields. The effect of the nanocrystal surface is modeled through the…