WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 11Citation - Scopus: 11The Effects of Native and Light Induced Defects on Optoelectronic Properties of Hydrogenated Amorphous Silicon-Germanium (a-Sige:h) Alloy Thin Films(Springer Verlag, 2010) Güneş, Mehmet; Yavaş, Mert; Klomfaß, Josef; Finger, FriedhelmEffects of native and light induced defects states in hydrogenated amorphous silicon-germanium alloy thin films with different Ge concentrations have been investigated by using steady-state photoconductivity, dual beam photoconductivity (DBP), transmission spectroscopy and photothermal deflection spectroscopy (PDS) techniques. In the annealed state, sub-bandgap absorption spectra obtained from both PDS and DBP overlap very well at energies above 1.4 eV. However, differences in α (hν) spectrum exist in the lower energy part of absorption spectrum. The α (hν) value measured at 1.0 eV is the lowest for 10% Ge sample and increases gradually as Ge content of the sample increases. In the light soaked state, time dependence of photoconductivity decay obeys to t -x power law, where x changes from 0.30 to 0.60 for samples with low Ge content and 0.05-0.1 for samples with high Ge content. Correspondingly, the increase of the sub-bandgap absorption coefficient at lower energies obeys to t y power law, where y values are lower than the x value of the same sample. It can be inferred that sub-bandgap absorption and photoconductivity measurements are not controlled by the same set of defects created in the bandgap of alloys. © 2009 Springer Science+Business Media, LLC.