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Dichroic organic films have found a broad application in various optoelectronic devices. One efficient method for the production of thin dichroic films is the deposition of the film onto aligning polymer surface. Scientists propose different explanations concerning the mechanisms of the molecules aligning. Here, we report the aligning of squaraine (Sq) molecules on the different aligning polymer surfaces, independent from the morphology of the Sq deposits. Aligned polytetrafluoroethylene (PTFE) layers were produced by either unidirectional hot friction transfer or by PTFE decomposition in vacuum with the activation of the gas by accelerated electrons and the consequent unidirectional rubbing with a cloth. Sq films grown on the aligned PTFE surfaces and on the nanostructured polycarbonate (PC) surfaces were found to exhibit dichroic optical absorption spectra. Despite different shape and orientation of the Sq crystals on the PTFE and the PC surfaces, the absorption of polarized light was shown to exhibit one pattern. Variations in the morphology of Sq films on different surfaces were explained by the competitive participation of different growth mechanisms, which depended on the properties of the deposited compound, the aligning layer and the growth conditions. The PTFE aligning layers can be useful in organic electronics due to low-temperature processing.

We present results of experiments to determine the dispersion of the plasmon modes associated with Au nanowire gratings with a fixed spatial frequency (3370 mm–1) and different slits between the nanowires fabricated using an interference (interferometric) lithography technique. Optical properties of fabricated plasmonic structures were studied using measurements of spectral and angular dependence of P- and S-polarized extinction in the wavelength range 0.4…1.1 μm, angles of incidence 10…70 degrees in conical mounting (at variable azimuth angle within the range φ = 0…90 degrees). It has been shown that in the grating with the average slit between the nanowires equal to half of the grating period at φ = 0 only local plasmons (LP) are excited by P-polarized light. When the azimuth angle changes from 0 to 90°, the intensity of the excited LP is smoothly “transferred” from P- to S-polarized excitation, and at φ ~ 30…45 degrees the intensities of the LP bands in both polarizations are approximately equal. However, in the sample with narrow slits between the nanowires (40 nm) we observe the mixed mode with excitation both surface plasmon-polariton (SPP) and LP in the P-polarization at φ = 0. With φ rising, the intensity of the mixed mode in P-polarization decreases and simultaneously the LP mode intensity in S-polarization increases.

We present experimental research on mechanical strains in the structure consisting of an array of silicon nanowires grown using the metal-enhanced CVD technique on boron-doped Si(111) and Si(100) substrates. Using the electron beam induced current on a cleaved substrate, electron spin resonance, and confocal micro-Raman spectroscopy, we found that growth of silicon nanowires on a native (silicon) substrate gives rise to a strain both of the substrate and grown nanowires, too. An occurrence of the strain in the substrate was revealed by an initiation of the electron spin resonance signal from boron atoms, which is not resolved usually in unstressed silicon due to a complex energy structure of a top of the valence band. Furthermore, the strain of the substrate was proved additionally by observation of spatial dependence of the current induced by electron beam on a cleaved substrate, and by the spectral shift of Raman peak related to 3С-Si near the interface “substrate – array of nanowires”. Mechanical strain in the nanowires was more pronounced in the Raman spectra, which also revealed their complex crystal structure consisting of cubic and hexagonal phases of silicon. Model of the strain rise is discussed.

Laterally ordered gold nanoisland arrays made using interference lithography has been investigated in this work as SERS substrates. The developed substrates demonstrate performance in enhancing Raman signal of common dye analyte (crystal violet (CV)) comparable to commercial SERS substrates, with the lowest detectable concentration of CV ~10−6…10−7 M. They can be reused after heat treatment at 300 °C without any drop of performance. Furthermore, we found a principal difference in the effect of annealing of SERS substrates before deposition of the analyte molecules and additional in situ annealing (with molecules) on the intensity of Raman signal. Possible physical origin of the latter effect has been discussed.

The influence of microwave radiation (2.45 GHz, 1.5 W cm−2, up to 80 s) on defects was studied in single crystals of n-6 H-SiC, n-GaAs, and epi-GaAs. The capture cross section of the charge carrier was found to change, and defect complexes were reconstructed because of the growing number of interstitial atoms in the near-surface layer. The correlation between the changes in the defect subsystem and deformation of the near-surface layer was analyzed. The possible mechanisms of the revealed effects are also discussed.

Multilayer organic and inorganic systems of thin solid films are widely used in novel optoelectronic devices. The required properties of the system depend on the morphology of the films and transition zone at interfaces. We studied the formation of deposits of fluorinated azo-dyes, polymethine, merocyanine and sulfur-terminated organic compounds (STOC) by evaporation and condensation in vacuum. The films were deposited on glass, silicon (Si), gold (Au) and polytetrafluoroethylene (PTFE) substrates. The influence of dye chemical structure and substrate on deposit morphology was studied using atomic force microscopy (AFM). Depending on the ratio between thermodynamic and kinetic processes, islands, crystalline aggregates or nano-structures were obtained. A difference in the morphology of the same dye solid, but deposited on various substrates was detected. Changes in the dye end or side groups caused variation in the morphology of the dye solid film. STOC formed a smooth film on the Au surface, while on the glass and PTFE it formed various islands. Thin films of the dyes in PTFE matrix exhibited unique stability to action of external factors. A new type of evaporable dyes with unsaturated reactive bond at the end was synthesized. Using new evaporation–activation–polymerization methods, the films with enhanced hardness and thermal stability were prepared from new dyes. Several dyes formed nano-micro-wires during the self-assembly process, in some cases between two neighboring Au strips. Adjusting the structure of the molecule by changing the end groups allows purposeful control of the deposit morphology on the selected surface.

Two types of ions (fluorine and titanium) are implanted into films of regio-regular poly(3-hexylthiophene-2,5-diyl) (rr-P3HT) spin-coated on glass substrates with subsequent annealing in argon atmosphere to modify their electrical properties and structure. The ion energy and fluence were within 0.2–40 keV and 1013–1015 cm−2 respectively. The dc resistance enhances after the intensive ion beam treatment while the ac impedance decreases. Ti ion implantation with 40 keV energy and 1014 cm−2 fluence induces decrease of the ac impedance by almost two orders of magnitude and appearance of the molecular hydrogen features in 1H NMR spectrum. The UV–VIS spectra of the films are blue shifted after their exposal to the ion beams, which correlates with the presence of oxygen. The ratio of the oxygen to carbon peak intensities ( ξ = O1s/C1s) in the XPS spectra is proposed as a measure for the local partial disturbance of the film. EPR spectra demonstrate formation of the paramagnetic states with g factor