http://dspace.nbuv.gov.ua:80/handle/123456789/114601 2026-04-13T05:40:38Z 2026-04-13T05:40:38Z Kostyukevych, S.A. Morozovska, A.N. Minko, V.I. Shepeliavyi, P.E. Kudryavtsev, A.A. Rubish, V.M. Rubish, V.V. Tverdokhleb, I.V. Kostiukevych, A.S. Dyrda, S.V. http://dspace.nbuv.gov.ua:80/handle/123456789/119231 2017-06-06T00:03:37Z 2004-01-01T00:00:00Z

Recording the high efficient diffraction gratings by using He-Cd laser Kostyukevych, S.A.; Morozovska, A.N.; Minko, V.I.; Shepeliavyi, P.E.; Kudryavtsev, A.A.; Rubish, V.M.; Rubish, V.V.; Tverdokhleb, I.V.; Kostiukevych, A.S.; Dyrda, S.V. High efficient holographic diffraction gratings with spatial frequencies from 600 to 3600 mm⁻¹ have been recorded using As₄₀S₆₀–хSeх (х = 0, 10, 20) photoresist layers and He-Cd laser operating at the wavelength λ = 440 nm. The investigation of the grating relief made by atomic force microscopy revealed that As₄₀S₆₀–хSeх resists allows one to record grating originals with profiles of various heights depending on the resist chemical composition, its etching and exposure times. We obtained typical spectral and angular dependences of the first order diffraction efficiency for the grating with the high modulation depth and groove profile close to the sinusoidal one. Comparing the recorded gratings with different spatial frequencies, exposure and etching times, we determined optimal recording conditions (exposure and etching times) in order to obtain gratings with the high diffraction efficiency.

2004-01-01T00:00:00Z Berezhinsky, L.I. Venger, E.F. Matyash, I.E. Serdega, B.K. http://dspace.nbuv.gov.ua:80/handle/123456789/119230 2017-06-06T00:02:57Z 2004-01-01T00:00:00Z

Spectra of the photo-electric phenomena physically differentiated on the light absorption factor Berezhinsky, L.I.; Venger, E.F.; Matyash, I.E.; Serdega, B.K. The pleochroism phenomena in photoconductivity of Ge samples and gate photoelectomotive force (photo-emf) of Si samples were experimentally investigated by a polarization modulation method. Anisotropy of dielectric properties was created by uniaxial compression. The spectral characteristics of the polarization difference describing above effects were measured. We found that: а) the pleochroism spectrum of photoconductivity is a derivative with respect to the absorption factor of a photocurrent function; b) the pleochroism spectrum of the gate photo-emf contains dichroic components, determined by the sample thickness, diffusion length of majority carriers, and layer thickness of a spatial charge.

2004-01-01T00:00:00Z Mahdjoub, A. Bouredoucen, H. Djelloul, A. http://dspace.nbuv.gov.ua:80/handle/123456789/119229 2017-06-06T00:04:05Z 2004-01-01T00:00:00Z

Photoluminescence characterization of Al/Al₂O₃/InP MIS structures passivated by anodic oxidation Mahdjoub, A.; Bouredoucen, H.; Djelloul, A. Metal-insulator-semiconductor (MIS) structures were produced by electron beam heating evaporation of Al₂O₃ on InP. Polyphosphate thin films with the thickness of 100 to 150 A were used to passivate the interface InP/Insulator. Photoluminescence spectra were obtained at low temperatures at the various stages of MIS-InP structure formation. At ambient temperature, photoluminescence topography made it possible to characterize the surface state after each technological stage. The interface degradation under the effect of repeated annealing is insignificant up to the temperatures close to 350 °C. Major radiative defects detected using photoluminescence spectrum with energies ranged from 0.95 to 1.15 eV were attributed to the impurity complexes of phosphorus vacancies, concentration of which is substantially reduced in the presence of anodic oxide.

2004-01-01T00:00:00Z Karachevtseva, L.A. http://dspace.nbuv.gov.ua:80/handle/123456789/119228 2017-06-06T00:02:47Z 2004-01-01T00:00:00Z

Two-dimensional photonic crystals as perspective materials of modern nanoelectronics Karachevtseva, L.A. Photonic crystals are a dynamic direction of modern solid state physics. Today the intensive research (more than 80 %) is concentrated on two-dimensional photonic crystals which have functionality of three-dimensional photonic crystals and rather simple manufacturing techniques and is directed towards the development of active and passive elements of the future integrated nanophotonic circuits. Twodimensional photonic macroporous silicon structures are perspective for development of photonic waveguides, thermal receivers due to occurrence of the powerful absorption bands in the infrared spectrum range. Formation macroporous silicon structures with nanocoatings expands its functionalities as photodetectors and light emitters.

2004-01-01T00:00:00Z