Physics / Fizik

Permanent URI for this collectionhttps://hdl.handle.net/11147/6

Browse

Filters

1997 - 19992

Settings

End date: 1999Scopus Q: search.filters.scopusQuartile.N/A

Search Results

Now showing 1 - 2 of 2
  • Conference Object
    Native and Light Induced Defect States in Wide Band Gap Hydrogenated Amorphous Silicon-Carbon (a-Si1 : H) Alloy Thin Films
    (Springer, 1997) Güneş, Mehmet
    In this study, wide band gap a-Si1-x C-x:H alloy thin films prepared with and without hydrogen diluation of (SiH4, CH4) were characterized using optical absorption, dark conductivity, steady-state photoconductivity, sub-bandgap absorption obtained with both photothermal deflection spectroscopy (PDS) and dual beam photoconductivity (DBP), and electron spin resonance (ESR) techniques. Experimental results of steady-state photoconductivity and sub-bandgap absorption for different generation rates were analyzed using a detailed numerical model based on Simmons-Taylor statistics. The densities, energy location and nature of the native and light induced defect states in diluted and undiluted a-Si1-xCx:H alloy thin films were derived from the best fits to the experimental data. The extracted parameters for defect states were compared with those of a-Si:H films both in the annealed and light degraded states.
  • Article
    Citation - WoS: 15
    Citation - Scopus: 14
    1/F-noise Study of Undoped Intrinsic Hydrogenated Amorphous Silicon Thin Films
    (American Physical Society, 1999) Güneş, Mehmet; Johanson, Robert E.; Kasap, Safa O.
    Conductance fluctuations in four samples of undoped intrinsic hydrogenated amorphous silicon (a-Si:H) were measured in the temperature range of 450 K to 500 K and for frequencies from 2 Hz to 3 kHz. The noise spectra divide into two regions that each fit a 1/fα power law but with different slope parameters α and different temperature dependences. At low frequencies, α is greater than unity and increases with temperature. At high frequencies, α is near 0.6 and temperature independent, but the noise magnitude decreases rapidly with temperature. We infer from the different dependences on temperature that the noise is generated by two independent mechanisms operating simultaneously in a-Si:H. We also observe that the 1/f noise exhibits a quadratic dependence on bias current and Gaussian statistics.