Selective enhancement of the hole photocurrent by surface plasmon–polaritons in layers of Ge/Si quantum dots

It is found that the integration of Ge/Si heterostructures containing layers of Ge quantum dots with twodimensional regular lattices of subwave holes in a gold film on the surface of a semiconductor leads to the multiple (to 20 times) enhancement of the hole photocurrent in narrow wavelength regions of the mid-infrared range. The results are explained by the light wave excitation of the surface plasmon–polaritons at the metal–semiconductor interface effectively interacting with intraband transitions of holes in quantum dots.     

Synthesis of substituted thiazoles and oxazoles from 2-amino-1-(p-nitrophenyl)ethanol

New thiourea derivatives have been synthesized by the condensation of 2-amino-1-(p-nitrophenyl)ethanol with aryl and alkyl isothiocyanates. Their cyclization with -bromoacetophenone and methyl monochloroacetate and also their desulfurization with yellow lead oxide have been studied.     

Suppression of hole relaxation in small Ge/Si quantum dots

We study the effect of quantum dot size on the mid-infrared photocurrent, photoconductive gain, and hole capture probability in ten-period p-type Ge/Si quantum dot heterostructures. The dot dimensions are varied by changing the Ge coverage during molecular beam epitaxy of Ge/Si(001) system in the Stranski–Krastanov growth mode while keeping the deposition temperature to be the same. A device with smaller dots is found to exhibit a lower capture probability and a higher photoconductive gain and photoresponse. The integrated responsivity in the mid-wave atmospheric window (λ = (3–5) μm) is improved by a factor of about 8 when the average in-plane dot dimension changes from 18 to 11 nm. The decrease in the dot size is expected to reduce the carrier relaxation rate due to phonon bottleneck by providing strong zero-dimensional quantum mechanical confinement.     

Using an comprehensive method for evaluation of environment state in a zone of influence of a tailing dam

The study of comprehensive assessment of the state of environmental objects in the zone of influence of the third tailing dam of former Khrustalnenskii miming enterprise (Fabrichnii section, Primorsky Krai) is presented. The means for ensuring its environmental and social safety have been proposed.     

Adhesive binders for layered alumopolymer composite materials

Results of studies of rheological and physico-mechanical properties of adhesive binders as components of adhesive prepregs based on glass fillers are presented. It was shown that VSK-14mR adhesive binder, which has low dynamic viscosity and high deformation and thermal strength characteristics, provides adhesive prepregs based on glass fiber rovings for layered alumopolymer composite materials.     

A study of the rheological properties of adhesive binders

Rheological properties of the VSK-14-2MR, VSK-14-3, and VSK-14-5M are studied depending on the temperature–time parameters of the technology for the production of glued prepregs. The temperature range of the processing of the binders of the given brands is determined, which allows the production of the glued prepreg with the optimal degree of properties.     

Intraband optical transitions of holes in strained SiGe quantum wells

Optical absorption spectra of polarized infrared radiation in p-type SiGe quantum-well structures have been investigated. Three types of structures with different magnitudes and signs of biaxial elastic strains have been studied. The light absorption factor has been found to double in the region of interband transitions under the in-plane tensile strain of the quantum-well heterojunction. The results are attributed to a change in the order of light- and heavy-hole bands caused by the tensile strain and to the formation of the ground state of charge carriers in the light-hole band.     

Syntheses in the field of quinoline derivatives

A number of 8-hydroxyquinolin-5-ylmethyl N, N-dialkyldithiocarbamates have been synthesized.For part III, see [3].