Browsing Τμήμα Φυσικής / Department of Physics by Author "Itskos, Grigorios"
Now showing items 1-20 of 41
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Article
Analysis of the transport process providing spin injection through an Fe/AlGaAs Schottky barrier
Hanbicki, A. T.; Van't Erve, O. M. J.; Magno, R.; Kioseoglou, G.; Li, C. H.; Jonker, B. T.; Itskos, Grigorios; Mallory, R.; Yasar, M.; Petrou, Athos Chariton (2003)Electrical injection through a reverse biased Fe/AlGaAs Schottky contact was used to obtain electron-spin polarizations in a GaAs quantum well. The analysis of the transport data using the Rowell criteria shows that ...
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Article
Concentration and excitation effects on the exciton dynamics of poly(3-hexylthiophene)/PbS quantum dot blend films
Tsokkou, Demetra; Itskos, Grigorios; Choulis, Stelios A.; Yarema, M.; Heiss, W.; Othonos, Andreas S. (2013)The dynamics of photoexcitations in hybrid blends of poly(3-hexylthiophene) (P3HT) conjugated polymer donor and oleic-acid capped lead sulfide (PbS) quantum dot (QD) acceptors of different concentrations - for light ...
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Article
Effects of the heteroepitaxial interface on spin injection in Fe/AlGaAs
Zega, T. J.; Stroud, R. M.; Hanbicki, A. T.; Kioseoglou, G.; Van't Erve, O. M. J.; Li, C. H.; Jonker, B. T.; Itskos, Grigorios; Mallory, R.; Yasar, M.; Petrou, Athos Chariton (2004)
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Article
Efficient dipole-dipole coupling of Mott-Wannier and Frenkel excitons in (Ga,In)N quantum well/polyfluorene semiconductor heterostructures
Itskos, Grigorios; Heliotis, G.; Lagoudakis, P. G.; Lupton, J.; Barradas, N. P.; Alves, E.; Pereira, S.; Watson, I. M.; Dawson, M. D.; Feldmann, J.; Murray, R.; Bradley, D. D. C. (2007)We investigate interactions between Mott-Wannier (MW) and Frenkel excitons in a family of hybrid structures consisting of thin organic (polyfluorene) films placed in close proximity (systematically adjusted by GaN cap layer ...
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Article
Efficient electrical spin injection from a magnetic metal/tunnel barrier contact into a semiconductor
Hanbicki, A. T.; Jonker, B. T.; Itskos, Grigorios; Kioseoglou, G.; Petrou, Athos Chariton (2002)We report electrical spin injection from a ferromagnetic metal contact into a semiconductor light emitting diode structure with an injection efficiency of 30% which persists to room temperature. The Schottky barrier formed ...
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Conference Object
Efficient förster transfer mediated by excitons in InGaN/GaN quantum well/polyfluorene heterostructures
Itskos, Grigorios; Heliotis, G.; Belton, C.; Watson, I. M.; Dawson, M. D.; Bradley, D. D. C.; Murray, R. (2007)We report on novel InGaN/GaN quantum well/polyfluorene heterostructures where efficient Förster energy transfer from the well to the organic layer occurs. We show that Mott-Wannier excitons dominate the quantum well ...
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Article
Electrical spin injection across air-exposed epitaxially regrown semiconductor interfaces
Park, Y. D.; Jonker, B. T.; Bennett, B. R.; Itskos, Grigorios; Furis, M.; Kioseoglou, G.; Petrou, Athos Chariton (2000)We have fabricated spin-polarized light-emitting diode structures via epitaxial regrowth of Znl-xMnxSe on air-exposed surfaces of AlyGal-yAs/GaAs quantum wells. No passivation procedures were used to protect or prepare the ...
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Conference Object
Electrical spin injection and band offsets in an n-type ferromagnetic semiconductor heterostructure: n-CdCr2Se4 / AlGaAs / GaAs
Jonker, B. T.; Hanbicki, A. T.; Kioseoglou, G.; Li, C. H.; Stroud, R. M.; Sullivan, J. M.; Erwin, S. C.; Lüpke, G.; Zhao, H. B.; Ren, Y. H.; Sun, B.; Itskos, Grigorios; Mallory, R.; Yasar, M.; Petrou, Athos Chariton (2003)The electrical spin injection and band offsets in an n-type ferromagnetic semiconductor heterostructure were discussed. The electrical spin injection from spin-LED structures showed defect-dominated electroluminescence. ...
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Conference Object
Electrical spin injection and band offsets in an n-type ferromagnetic semiconductor heterostructure: n-CdCr2Se4/AlGaAs/GaAs
Jonker, B. T.; Hanbicki, A. T.; Kioseoglou, G.; Li, C. H.; Stroud, R. M.; Sullivan, J. M.; Erwin, S. C.; Lüpke, G.; Zhao, H. B.; Ren, Y. H.; Sun, B.; Itskos, Grigorios; Mallory, R.; Yasar, M.; Petrou, Athos Chariton (Institute of Electrical and Electronics Engineers Inc., 2003)Electrical spin injection and band offsets in an n-type ferromagnetic semiconductor heterostructure of CdCr2Se4-AlGaAs-GaAs are studied. Epitaxially grown CdCr2Se4 films exhibit hysteresis behavior with significant remanence, ...
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Conference Object
Electrical spin injection from a magnetic schottky tunnel contact into a semiconductor
Jonker, B. T.; Hanbicki, A. T.; Itskos, Grigorios; Kioseoglou, G.; Petrou, Athos Chariton (2002)A report on the electrical spin injection from a magnetic Schottky tunnel contact into a semiconductor was presented. The temperature dependence of the optical polarization and corresponding spin injection efficiency was ...
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Article
Electronic and interface properties of polyfluorene films on GaN for hybrid optoelectronic applications
Itskos, Grigorios; Xristodoulou, X.; Iliopoulos, Eleftherios; Ladas, Spyridon; Kennou, Styliani; Neophytou, Marios; Choulis, Stelios A. (2013)Electronic and interface properties of spin-coated poly(9,9- dioctylfluorenyl-2,7-diyl) (PFO) films on GaN have been investigated in terms of their potential for optoelectronic applications. The PFO/GaN interface was studied ...
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Article
Emission from the stable Blatter radicalAAA
Karecla, G.; Papagiorgis, Panagiotis; Panagi, N.; Zissimou, Georgia A.; Constantinides, Christos P.; Koutentis, Panayiotis Andreas; Itskos, Grigorios; Hayes, Sophia C. (2017)1,3-Diaryl-1,4-dihydro-1,2,4-benzotriazin-4-yls are air stable organic radicals which have been exploited for their interesting magnetic properties. Herein, we present the optical properties of the "parent" radical namely ...
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Article
Erratum: Efficient dipole-dipole coupling of Mott-Wannier and Frenkel excitons in (Ga,In)N quantum well/polyfluorene semiconductor heterostructures (Physical Review B - Condensed Matter and Materials Physics (2007) 76, (035344))
Itskos, Grigorios; Heliotis, G.; Lagoudakis, P. G.; Lupton, J.; Barradas, N. P.; Alves, E.; Pereira, S.; Watson, I. M.; Dawson, M. D.; Feldmann, J.; Murray, R.; Bradley, D. D. C. (2008)
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Article
Excitation dynamics of a low bandgap silicon-bridged dithiophene copolymer and its composites with fullerenes
Othonos, Andreas S.; Itskos, Grigorios; Neophytou, Marios; Choulis, Stelios A. (2012)We report on excitation dynamics in pristine and bulk heterojunction films of the low bandgap silicon-bridged dithiophene copolymer poly[(4,4′-bis(2- ethylhexyl)dithieno[3,2-b:2′, 3′-d]silole)-2,6-diyl-alt-(4,7-bis(2- ...
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Article
Förster resonant energy transfer from an inorganic quantum well to a molecular material: Unexplored aspects, losses, and implications to applications
Itskos, Grigorios; Othonos, Andreas S.; Choulis, Stelios A.; Iliopoulos, Eleftherios (2015)A systematic investigation of Förster resonant energy transfer (FRET) is reported within a hybrid prototype structure based on nitride single quantum well (SQW) donors and light emitting polymer acceptors. Self-consistent ...
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Hybrid inorganic/organic semiconductor heterostructures with efficient non-radiative energy transfer
Heliotis, G.; Itskos, Grigorios; Murray, R.; Dawson, M. D.; Watson, I. M.; Bradley, D. D. C. (2006)A hybrid inorganic/organic semiconductor structure employing a polyfluorene thin films with Efficient non-radiative Förster resonant energy transfer (FRET) was fabricated. FRET is mediated by dipole-dipole interactions, ...
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Article
Hybrid polaritons in strongly coupled microcavities: Experiments and models
Lidzey, D. G.; Wenus, J.; Whittaker, D. M.; Itskos, Grigorios; Stavrinou, P. N.; Bradley, D. D. C.; Murray, R. (2004)We describe the fabrication of one-dimensional quantum microcavities containing two different layers of molecular J-aggregates. We show that strong coupling can occur between the confined cavity photon mode and the two ...
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Article
The influence of doping on the optoelectronic properties of PbS colloidal quantum dot solids
Papagiorgis, Panagiotis; Stavrinadis, A.; Othonos, Andreas S.; Konstantatos, G.; Itskos, Grigorios (2016)We report on an extensive spectroscopic investigation of the impact of substitutional doping on the optoelectronic properties of PbS colloidal quantum dot (CQD) solids. N-doping is provided by Bi incorporation during CQD ...
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Article
Influence of surface-related states on the carrier dynamics in (Ga,In)N/GaN single quantum wells
Othonos, Andreas S.; Itskos, Grigorios; Bradley, D. D. C.; Dawson, M. D.; Watson, I. M. (2009)We report on the influence of surface-related states on the relaxation of carriers within single (Ga,In)N/GaN quantum wells. Two identical samples that differ only in the thickness of the top GaN cap layer were studied. ...
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Article
Inkjet printing processing conditions for bulk-heterojunction solar cells using two high-performing conjugated polymer donors
Hermerschmidt, F.; Papagiorgis, Panagiotis; Savva, Achilleas; Christodoulou, Chris C.; Itskos, Grigorios; Choulis, Stelios A. (2014)We report the processing conditions for inkjet-printed active layers of organic photovoltaic (OPV) devices comprising bulk-heterojunction blends of the low bandgap conjugated polymer poly[(4,4′-bis(2-ethylhexyl)dithieno[3,2-b: ...