The Influence of Film Thickness on Annealing-Induced Grain Growth in Pt Films

Technical Physics - Pt films with thickness h = 20–100 nm deposited on oxidized с-Si(100) substrate have been subjected to vacuum annealing at 500°C for 1 h, which resulted in...     

Advantages of STED-Inspired 3D Direct Laser Writing for Fabrication of Hybrid Nanostructures

We present a new method of additive laser technology referred to as STED nanolithography technique. This technique provides a means for fabrication of 3D dielectric and plasmonic composite nanostructures. The new technology is of the utmost interest for the electronics manufacturing industry, in particular, for formation of specific hybrid (metal–dye) nanostructures, which can be utilized as luminescent markers in biology, medicine, criminalistics, and the trade industry. In the present study, we demonstrate the advantages of STED-inspired nanolithography for fabrication of metallic and hybrid nanostructures. The 3D-scanning setup implemented offers the possibility to form both periodic and aperiodic nanostructured arrays. We show the possibility to decrease substantially the lateral size of the lines formed with the use of STED nanolithography as compared to the direct laser writing (DLW) method. The STED nanolithography technique proposed provides a means for synthesizing metallic nanoparticles in the specified points of the volume of the studied object in vivo. In addition, we demonstrate the synthesis of metallic lines by means of STED nanolithography. Moreover, nanometer spatial precision of positioning of the synthesized nanoobjects is achieved. Therefore, it is possible to obtain significant local enhancement of the emission of luminescent markers (surface enhanced luminescence) at any desired point or area of the sample due to plasmonic enhancement of the electromagnetic fields near the surface of metallic nanostructures.     

Synthesis and luminescent properties of neutral Eu(III) and Gd(III) complexes with 1-(1,5-dimethyl-1h-pyrazol-4-yl)-4,4,4-trifluoro-1,3-butanedione and 4,4,5,5,6,6,6-heptafluoro-1-(1-methyl-1H-pyrazol-4-yl)-1,3-hexanedione

Neutral [EuL₃Phen] complexes were synthesized by the reaction of EuCl₃ with heterocyclic diketones-1-(1,5-dimethyl-1H-pyrazol-4-yl)-4,4,4-trifluoro-1,3-butanedione and 4,4,5,5,6,6,6-heptafluoro-1-(1-methyl-1H-pyrazol-4-yl)-1,3-hexanedione—and 1,10-phenanthroline (Phen) in an aqueous alcohol solution in the presence of NaOH. The reaction of GdCl₃ with the same diketones under analogous conditions, but without adding 1,10-phenanthroline, yielded [GdL₃(H₂O)₂] complexes. The composition of the complexes was determined by elemental analysis, and their optical and luminescent properties were examined.     

The Influence of Film Thickness on the Annealing-Induced Changes of Texture and of the Fraction of Crystalline Phase in Pt Films

Technical Physics - Textured Pt films 20–80 nm in thickness magnetron-sputtered on an oxidized c-Si(100) substrate have been annealed in vacuum at 500°C for 60 min. The texture...     

Destruction of Doped Lithium Tetraborate under Exposure to Ionizing and Laser Radiation

Optics and Spectroscopy - The results of the study of the degradation of thermoluminescent materials Li2B4O7:Be + Mn and Li2B4O7:Zn + Mn under the effect of radiation (pulsed electron beam) and...     

Excitation and de-excitation cross sections for light-emitting nanoclusters in rare earth-doped silicon

The excitation and de-excitation cross sections of light-emitting nanoclusters in rare earth-doped silicon are calculated. Two processes of de-excitation are considered: emission of a photon by the center and transfer of the cluster energy to a scattered electron. The cross sections of these two processes are shown to be large. Therefore, de-excitation has a significant effect on the concentration of excited rare-earth centers in silicon.     

Organic light-emitting diode with an emitter based on a planar layer of CdSe semiconductor nanoplatelets

Colloidal CdSe semiconductor nanoplatelets with characteristic longitudinal sizes of 20–70 nm and thicknesses of several atomic layers are synthesized. The spectra and kinetics of the photoluminescence of these quasi-two-dimensional nanostructures (quantum wells) at room and cryogenic temperatures are investigated. A hybrid light-emitting diode with the electron and hole transport layers based on TAZ and TPD organic compounds, respectively, and the active “emissive” element based on a layer of such single-component nanoplatelets is designed. The spectral and electrical characteristics of the fabricated device, emitting at a wavelength of λ = 515 nm, are determined. The use of quasi-two-dimensional nanostructures of this kind (nanoplatelets) is promising for the fabrication of hybrid light-emitting diodes with pure colors.     

Effect of Bonding Scandium(III) ion to 1,3-Diketones on Their Luminescent Properties

We study the influence of bonding Sc(III) ion with 1,3-diketonate ligands on luminescent properties of 1,3-diketones in two complexes by means of optical spectroscopy. We show that the sensitization of the ligand luminescence of the complexes obtained increases from 0.8% for neat ligands and to 4% for the synthesized compounds; this fact is confirmed by the quantum yield measurements.