Articole din publicaţii internaţionale: Recent submissions

  • Energy band structure and optical constants of ZnAs2 crystals 
    STAMOV, I. G.; SYRBU, N. N.; URSAKI, V. V.; DOROGAN, A. V. (ELSEVIER, 2012)
    The fine structure of the Fabry–Perot interference as well as the interference of ordinary and extraordinary waves is investigated in ZnAs2 crystals. ε1, ε2, n and k optical constants are calculated in a wide spectral range ...
  • Interference of ordinary and extraordinary waves in AgAsS2 crystals 
    SYRBU, N. N.; STAMOV, I. G.; URSAKI, V. V.; PARVAN, V.; IVANENCO, Yu. (ELSEVIER, 2012)
    The anisotropy of the near-bandgap absorption is investigated in AgAsS2 crystals. The refraction indices, n and n respectively for the Ec and Ec polarizations as well as the spectral dependence of the refraction ...
  • Optical spectra and energy band structure of AgAsS2 crystals 
    STAMOV, I. G.; SYRBU, N. N.; URSAKI, V. V.; PARVAN, V. (ELSEVIER, 2012)
    Ground and excited states of three exciton series are observed in the region of fundamental absorption edge of AgAsS2 crystals. The contours of exciton reflection spectra are calculated and the main parameters of excitons ...
  • Resonance Raman scattering and excitonic spectra in TlInS2 crystals 
    ZALAMAI, V. V.; STAMOV, I. G.; SYRBU, N. N.; URSAKI, V. V.; DOROGAN, V. (ELSEVIER, 2015)
    The excitons ground and excited states for Ea and Eb polarizations in absorption and reflection spectra of TlInS2 crystals were detected. The fundamental parameters of excitons and bands were determined at k=0. The ...
  • Sharp variations in the temperature dependence of optical reflectivity from AlN/GaN heterostructures 
    URSAKI, V. V.; TIGINYANU, I. M.; SYRBU, N. N.; ZALAMAI, V. V.; HUBBARD, S.; PAVLIDIS, D. (IOP Publishing, 2002)
    Sharp variations in optical reflectivity were observed when cooling and heating AlN/GaN heterostructures on sapphire substrates between room temperature and 10 K. The reflectivity was found to decrease at a definite ...
  • Cathodoluminescence characterization of rare earth doped composite materials based on porous GaP 
    SÁNCHEZ, B.; MÉNDEZ, B.; PIQUERAS, J.; SIRBU, L.; TIGINYANU, I. M.; URSAKI, V. V. (Springer Nature Switzerland, 2008)
    Porous GaP layers doped with erbium or europium elements have been obtained by electrochemical etching and further impregnation processes. The thermal treatments for optical activation of rare earth (RE) ions lead to partial ...
  • Resonance Raman scattering in CuGaxAl1-xS2crystals 
    SYRBU, N. N.; TIGINYANU, I. M.; URSAKI, V. V.; DOROGAN, A. V. (IOP Publishing, 2008)
    The change of polarization of the resonant Raman scattering lines is studied in CuGaxAl1−xS2 crystals with x equal to 1, 0.95 and 0.9 assuming resonance conditions with 4880 and 4765 Å Ar laser lines. Linear and circular ...
  • Impurity centers in ZnSe:Na crystals 
    COLIBABA, G. V.; NEDEOGLO, D. D.; URSAKI, V. V. (ELSEVIER, 2011)
    The influence of sodium impurity on photoluminescence (PL) spectra of ZnSe crystals doped in a growth process from a Se+Na melt is investigated. It is shown that the introduction of the impurity results in emergence of ...
  • Temperature dependence of the photoluminescence spectra in AgGaS2 
    RICCI, P. C.; ANEDDA, A.; CORPINO, R.; CARBONARO, C. M.; MARCEDDU, M.; TIGINYANU, I. M.; URSAKI, V. V. (ELSEVIER, 2005)
    The Silver Gallium Sulfide (AgGaS2) ternary compound is a wide bandgap semiconductor (about 2.7eV) whose photoluminescence properties are characterized by excitons and donor–acceptor pairs recombinations. We have performed ...
  • Optical spectra in the region of exciton resonances in quantum wells and quantum dots of In0.3Ga0.7As/GaAs heterostructures 
    SYRBU, N. N.; DOROGAN, V.; DOROGAN, A.; VIERU, T.; URSAKI, V. V.; ZALAMAI, V. V. (ELSEVIER, 2012)
    The transparency, reflection and luminescence spectra of In0.3Ga0.7As structures with 8nm thickness and quantum wells limited by the barrier layer GaAs of a 9nm (upper layer) and 100nm (bottom layer) thickness had been ...
  • Luminescent and Photoconductive Properties of AgGa2.5In2.5S8 and CuGa2.5In2.5S8 New Semiconductors 
    ANEDDA, A.; SERPI, A.; MOLDOVYAN, N. A.; TIGINYANU, I. M.; URSAKI, V. V. (IOP Publishing, 1993)
    Results of a complex study of photoluminescence (PL), photoconductivity (PC) and photo-voltaic (PV) spectra in AgGa2.5In2.5S8 and CuGa2.5In2.5S8 single crystals are presented. The values of indirect (Egi=2.25 eV) and direct ...
  • Energy band structure and Frenkel excitons in PbGa2S4 
    STAMOV, I. G.; SYRBU, N. N.; URSAKI, V. V.; PARVAN, V. I.; ZALAMAI, V. V. (ELSEVIER, 2012)
    Optical reflection spectra are measured and calculated in PbGa2S4 crystals in the region of resonances related to excitons with large oscillator strength and binding energy (Frenkel excitons). The splitting of the upper ...
  • Er- and Eu-doped GaP-oxide porous composites for optoelectronic applications 
    SIRBU, L.; URSAKI, V. V.; TIGINYANU, I. M.; DOLGALEVA, Ksenia; BOYD, Robert W. (WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, 2007)
    We demonstrate the controlled preparation of Er- and Eu-doped GaP-oxide porous composites. The fabrication procedure entails the use of porous semiconductor templates and the impregnation of rare earth ions from a rare ...
  • Red and green nanocomposite phosphors prepared from porous GaAs templates 
    SYRBU, Lilian; URSAKI, V. V.; TIGINYANU, I. M.; DOLGALEVA, Ksenia; BOYD, Robert W. (IOP Publishing, 2007)
    Rare-earth-containing oxide nanocomposites are prepared in a controlled fashion from porous GaAs templates. The initial porous GaAs network is replaced by a β-Ga2O3 one during annealing at temperatures from 500 to 900 °C. ...
  • Large oscillator strength excitons in PbGa2S4 crystals 
    SYRBU, N. N.; PARVAN, V. I.; URSAKI, V. V. (ELSEVIER, 2012)
    Exciton states with a large oscillator strength (transverse–longitudinal splitting of 50meV) and binding energy of 290meV have been observed in PbGa2S4 crystals. The ground exciton states are stable up to the room temperature. ...
  • Body zero frequency modes in photonic crystals of nanopores and nanocylinders 
    SERGENTU, Vladimir; URSAKI, Veaceslav; SIRBU, Lilian (WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, 2013)
    In this paper, we demonstrate that body zero frequency modes can exist at extremely low frequencies in a system of nanocylinders made of non-dissipative material. Such kind of modes is not specific to single nanocylinders, ...
  • Mechanical properties and Raman scattering investigation under indentation of CdGa2S4 and CdGa2Se4 
    SHIKIMAKA, O.; BURLACU, A.; GRABCO, D.; PARVAN, V.; PYRTSAC, C.; URSAKI, V. (IOP Publishing, 2016)
    The behavior of CdGa2S4 and CdGa2Se4 single crystalline semiconductors under Berkovich indentation of the (1 1 2) face in the load range of 10–700 mN has been investigated. Values of hardness and Young’s modulus have been ...
  • Improvement of InP crystalline perfection by He+-implantation and subsequent annealing 
    TIGINYANU, I. M.; TERLETSKY, A. I.; URSAKI, V. V. (ELSEVIER, 1995)
    The influence has been studied of 100-keV He+-ion implantation and subsequent thermal annealing on Raman scattering spectra of LEC-grown InP single crystals with (100)- and (111)-crystallographic orientations of the surface. ...
  • Polariton emission from CuGaSe2 crystals 
    SYRBU, N. N.; TIGINYANU, I. M.; URSAKI, V. V.; TEZLEVAN, V. E.; ZALAMAI, V. V.; NEMERENCO, L. L. (ELSEVIER, 2005)
    The value of longitudinal–transverse splitting ωLT equal to 2.5–2.8meV and the translation mass M=2.5m0 were determined for the A exciton as a result of investigation of the reflectivity and luminescence spectra of CuGaSe2 ...
  • Luminescence properties of a ZnO–In2O3 composite 
    URSAKI, V. V.; TIGINYANU, I. M.; BURLACU, A.; ZALAMAI, V.; JITARI, V. F. (WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, 2006)
    ZnO–In2O3 composite was prepared by thermal annealing of ZnIn2S4 crystals. Energy dispersive X-ray analysis demonstrated that annealing results in the formation of a composite consisting of ZnO and In2O3 phases with the ...

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