Semiconductor quantum dots (QDs) are widely used in light-emitting diodes and solar cells. Electrochemical modulation is a good way to understand the electrical and optical properties of QDs. In this work, the effects of electrochemical control on photoluminescence (PL) spectra in core/shell CdSe/ZnS QD films are studied. The results show different spectral responses for surface emission and co...

We study a possible physical realization of a quantum controlled-NOT gate with the use of two weakly coupled asymmetric quantum dots. Solving the time-dependent Schrödinger equation for the model twoelectron system, we simulate the infrared-radiation-induced quantum transitions that correspond to basic gate operations. We require the transition probabilities to be close to 1 and optimize the pa...

We review our experimental study on the electron transport in quantum dots, formed in the two-dimensional electron gas in GaAs/AlGaAs heterostructures. Single electron transport with well-resolved zero-dimensional energy levels is described for both single and coupled quantum dots. Effects of microwave irradiation are also studied, and photon assisted tunneling was observed between two discrete...

We study the effect of an electric field on an electron-hole pair in an asymmetric system of vertically coupled self-assembled quantum dots taking into account their nonperfect alignment. We show that the nonperfect alignment does not qualitatively influence the exciton Stark effect for the electric field applied in the growth direction, but can be detected by application of a perpendicular ele...

A two-dimensional array of quantum dots in a magnetic field is considered. The electrons in the quantum dots are described as unitary random matrix ensembles. The strength of the magnetic field is such that there is half a flux quantum per plaquette. This model exhibits the Integer Quantum Hall Effect. For N electronic states per quantum dot the limit N → ∞ can be solved by a saddle point integ...

we report the growth by ion exchange synthesis of zns nanoparticles in mcm-41 matrices using zn (ch3coo)2 and na2s starting sources. the final product (zns/mcm-41) was characterized by x-ray diffraction (xrd) pattern, transmission electron microscopy (tem), scanning electron microscopy (sem), infrared spectrometry (ir) and uv-vis spectroscopy. its crystalline structure and morphology was studie...

A model that explains the unusual characteristics of the AlGaAs/GaAs modulation-doped field-effect transistor (MODFET) with InAs quantum dots incorporated in the GaAs channel is presented. It is shown that the negative charge of electrons confined in quantum dots decreases the threshold gate–drain voltage at which the channel is fully depleted. This provides an impact ionization of quantum dots...

We control the electrostatic environment of a single InAsP quantum dot in an InP nanowire with two contacts and two lateral gates positioned to an individual nanowire. We empty the quantum dot of excess charges and apply an electric field across its radial dimension. A large tuning range for the biexciton binding energy of 3 meV is obtained in a lateral electric field. At finite lateral electri...

Background and Aims: Quantum dots (QDs), as colloidal nanocrystalline semiconductors, present QD wavelengths in terms of biomedical assays and imaging, though the high toxicity of their core demands to be taken into consideration. Investigating this subject is taken into account as an important concept   concerning use of these nanoparticles in the medical applications. Materials a...

We report transport measurements as a function of bias in open semiconductor quantum dots. These measurements are well described by an effective electron temperature derived from Joule heating at the point contacts and cooling by Wiedemann-Franz out-diffusion of thermal electrons. Using this model, we propose and analyze a quantum dot based sensor which measures absolute magnetic field at micro...