Browsing by Author "Lioutas, Ch B."
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Influence of grain size on ultrafast carrier dynamics in thin nanocrystalline silicon films
Lioudakis, Emmanouil E.; Othonos, Andreas S.; Nassiopoulou, Androula Galiouna; Lioutas, Ch B.; Frangis, N. (2007)The ultrafast carrier dynamics in thin nanocrystalline silicon films (10 and 20 nm thick) on quartz over a broad spectral range using optical pumping at a moderate fluence of 2.5 mJ cm2 were studied. The films were composed ...
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Article
The role of surface vibrations and quantum confinement effect to the optical properties of very thin nanocrystalline silicon films
Lioudakis, Emmanouil E.; Antoniou, Antreas; Othonos, Andreas S.; Christofides, Constantinos; Nassiopoulou, Androula Galiouna; Lioutas, Ch B.; Frangis, N. (2007)We report on a spectroscopic study of very thin nanocrystalline silicon films varying between 5 and 30 nm. The role of quantum confinement effect and surface passivation of nanograins in optical properties are examined in ...
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Thermoelectric properties of highly efficient Bi-doped Mg2Si1−x−ySnxGey materials
Khan, A. U.; Vlachos, N. V.; Hatzikraniotis, E.; Polymeris, G. S.; Lioutas, Ch B.; Stefanaki, E. C.; Paraskevopoulos, K. M.; Giapintzakis, John; Kyratsi, Theodora (2014)In this work, Bi-doped Mg2Si1−x−ySnxGey (x=0.4 and y=0.05) solid solutions with the nominal Bi content of 0⩽z⩽0.035 were synthesized by solid state synthesis and sintering via hot pressing, and were studied in terms of ...
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Thermoelectric properties of nanocrystalline PbTe synthesized by mechanical alloying
Papageorgiou, Ch; Hatzikraniotis, E.; Lioutas, Ch B.; Frangis, N.; Valassiades, O.; Paraskevopoulos, K. M.; Kyratsi, Theodora (2010)In this work, nanocrystalline lead telluride powder was synthesized from high-purity elements by mechanical alloying by means of a planetary ball-milling procedure. The milling medium was tungsten carbide, and the diameter ...
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Transient photoinduced absorption in ultrathin as-grown nanocrystalline silicon films
Lioudakis, Emmanouil E.; Othonos, Andreas S.; Lioutas, Ch B.; Vouroutzis, N. (2008)We have studied ultrafast carrier dynamics in nanocrystalline silicon films with thickness of a few nanometers where boundary-related states and quantum confinement play an important role. Transient non-degenerated ...