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Site-controlled growth of InP/GaInP2 quantum dots has been demonstrated by means of selective epitaxy technique realized with a SiO2 mask and e-beam lithography. Critical influence of the growth temperature on QD formation in the selective epitaxy has been demonstrated. Role of SiO2 deposition technique on the selective epitaxy of QD's has been established. [ABSTRACT FROM AUTHOR]

The topic of the work is laser power converters (LPCs) for wavelength range of λ=1 – 1.1 µm based on metamorphic InGaAs heterostructures. Variation of the indium concentration "x" in the InxGa1-xAs active area from 0.23 to 0.18 and the use of a distributed Bragg reflector have been investigated. As a result of the voltage increase (due to the minimum concentration of indium in a LPC with indium concentration of about 18% in the active region), the following record efficiency (for such a type of LPC) for monochromatic light conversion has been achieved: about 52% at 1.06 µm and 55% at 1.02 µm. Moreover, the use of a Bragg reflector has allowed stabilizing high spectral response at the InGaAs absorption edge (x=0.18), and demonstrating more than 47% efficiency at a real operating temperature range (higher than +50°C) at 1.06 µm. [ABSTRACT FROM AUTHOR]

The topic of the work is the metamorphic InGaAs heterostructure for laser power converters with λ=1064 nm. The problem of conversion efficiency under various conditions of incident radiation is investigated: with uniform illumination with a Xe-lamp, with a continuous high-power laser, and with a pulsed laser. The thermal coefficient α=ΔV/ΔT of overheating is calculated for continuous laser. An increasing contribution of resistive losses, associated with the spreading resistance, for a focused laser beam (when the focus spot is smaller than the photoactive area of a sample) is discussed. It has been demonstrated that with a unfocused laser beam (the mode corresponding to the practical case of wireless energy transmission), the conversion efficiency of laser radiation is compared with the efficiency under a Xe-lamp. For laser power converters with optimal (according to calculated from spectral characteristics MCC diffusion length) thickness, the efficiency of more than 48% (λ=1064 nm) within 1.3–13 W/cm2 incident power was demonstrated with 50.6% maximum at 5.2 W/cm². [ABSTRACT FROM AUTHOR]

Resistance-less dark IV-curves of GaAs solar cells with and without quantum-dimensional objects allied to both quantum dot and quantum well have been obtained and analyzed. Anomalous large increase of the pre-exponential factors was observed in tested (with quantum objects) p-n junctions. According to proposed interpretation embedding of quantum objects in p-n junction created new current flow mechanisms. As a result current flows throught recombination transitions inside quantum objects in space charge region of p-n junction. [ABSTRACT FROM AUTHOR]

By using a Regge-pole model for vector meson production (VMP), that successfully describes the HERA data, we analyse the connection of VMP cross sections in photon-induced reactions at HERA with those in ultra-peripheral collisions at the Large Hadron Collider (LHC). The role of the low-energy behaviour of VMP cross sections in γρ collisions is scrutinized. [ABSTRACT FROM AUTHOR]

We append a simple Pomeron pole amplitude by t and Q2, MV dependencies inspired by geometrical ideas. The experimentally transition from soft to hard dynamics is realized by the introduction of a two-component Pomeron with different Q2 and MV-dependent residues. A unified description of deeply virtual Compton scattering (DVCS), of exclusive electroproduction of all vector mesons as well as of elastic pp scattering is suggested. [ABSTRACT FROM AUTHOR]

We report on recent calculations of low missing mass single (SD) and double (DD) diffractive dissociation at LHC energies. The calculations are based on a dual-Regge model, dominated by a single Pomeron exchange. The diffractively excited states lie on the nucleon trajectory N*, appended by the isolated Roper resonance. Detailed predictions for the squared momentum transfer and missing mass dependence of the differential and integrated single-and double diffraction dissociation in the kinematical range of present and future LHC measurements are given. [ABSTRACT FROM AUTHOR]