Browsing by Subject "Semiconductor quantum dots"

Article

Comparing intracellular stability and targeting of sulfobetaine quantum dots with other surface chemistries in live cells

Muro, E.; Fragola, A.; Pons, T.; Lequeux, N.; Ioannou, Androulla; Skourides, Paris A.; Dubertret, B. (2012)

The in vivo labeling of intracellular components with quantum dots (QDs) is very limited because of QD aggregation in the cell cytoplasm and/or QD confinement into lysosomal compartments. In order to improve intracellular ...

Article

Competing broken-symmetry and rotationally symmetric spin-singlet states in a few-electron quantum dot in a magnetic field

Avetisyan, A.; Moulopoulos, Konstantinos; Djotyan, Anahit P. (2008)

On the basis of developed variational many-body approach, within a second quantized formulation, the nature of the ground state of a few-electron system in a parabolic two-dimensional (2D) quantum dot (QD) is theoretically ...

Article

Concentration and excitation effects on the exciton dynamics of poly(3-hexylthiophene)/PbS quantum dot blend films

Tsokkou, Demetra; Itskos, Grigorios; Choulis, Stelios A.; Yarema, M.; Heiss, W.; Othonos, Andreas S. (2013)

The dynamics of photoexcitations in hybrid blends of poly(3-hexylthiophene) (P3HT) conjugated polymer donor and oleic-acid capped lead sulfide (PbS) quantum dot (QD) acceptors of different concentrations - for light ...

Article

Core-shell PbS/Sn:In2O3 and branched PbIn2S4/Sn:In2O3 nanowires in quantum dot sensitized solar cells

Zervos, Matthew; Vasile, Eugeniu; Tanasǎ, Eugenia; Othonos, Andreas S. (2017)

Core-shell PbS/Sn:In2O3 and branched PbIn2S4/Sn:In2O3 nanowires have been obtained via the deposition of Pb over Sn:In2O3 nanowires and post growth processing under H2S between 100 C-200 C and 300 C-500 C respectively. The ...

Article

Core-shell PbS/Sn:In2O3 and branched PbIn2S4/Sn:In2O3 nanowires in quantum dot sensitized solar cells

Zervos, Matthew; Vasile, E.; Vasile, E.; Othonos, A. (2017)

Core-shell PbS/Sn:In2O3 and branched PbIn2S4/Sn:In2O3 nanowires have been obtained via the deposition of Pb over Sn:In2O3 nanowires and post growth processing under H2S between 100 C-200 C and 300 C-500 C respectively. The ...

Conference Object

Coulomb repulsive correlation in A3B5 semiconductor quantum dots in the presence of a magnetic field

Avetisyan, A. A.; Djotyan, Anahit P.; Moulopoulos, Konstantinos (2006)

The ground state total and correlation energies of a negative ion-electron and electron-electron systems in a parabolic QD with standard dispersion law are theoretically investigated in an external magnetic field by a ...

Article

Coulomb repulsive correlation in systems with radial confinement: Quantum dots and the Overhauser model in an external magnetic field

Avetisyan, A. A.; Moulopoulos, Konstantinos; Djotyan, Anahit P. (2006)

The ground-state correlation energy of an electron-negative ion system in a spherical quantum dot (QD) with parabolic confinement in an external homogeneous magnetic field is investigated. Both cases of finite and infinite ...

Article

Current transport in semiconductor nanowires with built-in barriers based on a 1D transfer matrix calculation

Zervos, Matthew; Pelekanos, N. T. (2008)

A one dimensional (1D) transfer matrix calculation of current transport in semiconductor nanowires with built-in barriers is described within the effective mass approximation by taking into account (i) the quantum confinement ...

Article

Current Transport Properties of CuS/Sn:In2O3 versus CuS/SnO2 Nanowires and Negative Differential Resistance in Quantum Dot Sensitized Solar Cells

Zervos, Matthew; Vasile, Eugeniu; Tanasǎ, Eugenia; Karageorgou, E.; Othonos, Andreas S. (2016)

The structural, optical, and electrical transport properties of nanowires obtained by the deposition of Cu over Sn doped In2O3 and SnO2 nanowires followed by processing under H2S between 100 and 500°C have been investigated ...

Article

Defect states of chemical vapor deposition grown GaN nanowires: Effects and mechanisms in the relaxation of carriers

Tsokkou, Demetra; Othonos, Andreas S.; Zervos, Matthew (2009)

Carrier relaxation in GaN nanowires, grown by atmospheric pressure chemical vapor deposition, via direct nitridation of Ga with NH3 at 950 °C has been investigated in detail. Differential absorption measurements reveal a ...

Article

Defect states of chemical vapor deposition grown GaN nanowires: Effects and mechanisms in the relaxation of carriers

Tsokkou, D.; Othonos, A.; Zervos, Matthew (2009)

Carrier relaxation in GaN nanowires, grown by atmospheric pressure chemical vapor deposition, via direct nitridation of Ga with NH3 at 950 °C has been investigated in detail. Differential absorption measurements reveal a ...

Article

Electrical, structural, and optical properties of sulfurized Sn-doped In2O3 nanowires

Zervos, Matthew; Mihailescu, C. N.; Giapintzakis, Ioannis; Othonos, Andreas S.; Travlos, A.; Luculescu, C. R. (2015)

Sn-doped In2O3 nanowires have been grown on Si via the vapor-liquid-solid mechanism at 800 °C and then exposed to H2S between 300 to 600 °C. We observe the existence of cubic bixbyite In2O3 and hexagonal SnS2 after processing ...

Article

Electrical, structural, and optical properties of sulfurized Sn-doped In2O3 nanowires

Zervos, Matthew; Mihailescu, C. N.; Giapintzakis, John; Othonos, A.; Travlos, A.; Luculescu, C. R. (2015)

Sn-doped In2O3 nanowires have been grown on Si via the vapor-liquid-solid mechanism at 800 °C and then exposed to H2S between 300 to 600 °C. We observe the existence of cubic bixbyite In2O3 and hexagonal SnS2 after processing ...

Article

Electronic structure of piezoelectric double-barrier InAs/InP/InAs/InP/InAs (111) nanowires

Zervos, Matthew; Feiner, L.-F. (2004)

The numerical self-consistent solution of the Poisson-Schrodinger equations in cylindrical coordinates for calculating electronic states in the effective mass approximation was implemented. High accuracy and rapid convergence ...

Article

Exciton-donor complexes in semiconductor quantum dots in a magnetic field: Infinite and finite potential barriers

Avetisyan, A.; Djotyan, Anahit P.; Kazaryan, E.; Moulopoulos, Konstantinos (2008)

The binding energy of the ground state of a charged exciton-donor complex in a spherical semiconductor quantum dot with infinite and finite potential barriers as well as the oscillator strength for the optical transition ...

Conference Object

Few-electron systems in a quantum dot in a magnetic field: The Wigner molecule and paired electron phases

Avetisyan, A. A.; Moulopoulos, Konstantinos (2006)

We have developed a variational many-body description for few-electron systems in a parabolic quantum dot in an external magnetic field. The ground state energy of the electronic system has been theoretically investigated ...

Article

InAs quantum dots grown by molecular beam epitaxy on GaAs (211)B polar substrates

Zervos, Matthew; Xenogianni, C.; Deligeorgis, G.; Androulidaki, M.; Savvidis, P. G.; Hatzopoulos, Z.; Pelekanos, N. T. (2006)

InAs nanostructures were grown by molecular beam epitaxy on GaAs (211)B at temperatures between 400-530 °C and growth rates that were varied between 0.1 to 0.02 mono-layers (ML) per second. For temperatures up to 500 °C ...

Article

Intein-mediated site-specific conjugation of Quantum Dots to proteins in vivo

Charalambous, Anna; Andreou, Maria I.; Skourides, Paris A. (2009)

We describe an intein based method to site-specifically conjugate Quantum Dots (QDs) to target proteins in vivo. This approach allows the covalent conjugation of any nanostructure and/or nanodevice to any protein and thus ...

Article

Oblique Hanle measurements of InAsGaAs quantum dot spin-light emitting diodes

Itskos, Grigorios; Harbord, E.; Clowes, S. K.; Clarke, E.; Cohen, L. F.; Murray, R.; Van Dorpe, P.; Van Roy, W. (2006)

We report on studies of electrical spin injection from ferromagnetic Fe contacts into semiconductor light emitting diodes containing single layers of InAsGaAs self-assembled quantum dots (QDs). An oblique magnetic field ...

Article

Optical properties of organic semiconductor blends with near-infrared quantum-dot sensitizers for light harvesting applications

Itskos, Grigorios; Othonos, Andreas S.; Rauch, T.; Tedde, S. F.; Hayden, O.; Kovalenko, M. V.; Heiss, W.; Choulis, Stelios A. (2011)

We report an optical investigation of conjugated polymer (P3HT)/fullerene (PCBM) semiconductor blends sensitized by near-infrared absorbing quantum dots (PbS QDs). A systematic series of samples that include pristine, ...