KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Author: search.filters.author.Supadech, S.Subject: search.filters.subject.Shot noise

Search Results

Now showing 1 - 2 of 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    White noise due to photocurrents in planar MSM structures on low-resistivity Si
    (2003-10-01)
    Khunkhao, S.
    ;
    Niemcharoen, S.
    ;
    Supadech, S.
    ;
    Sato, K.
    The noise due to photocurrent at low frequencies (3-100 kHz) has been observed of planar aluminum/n-type silicon/aluminum (Al/n-Si/Al) structures based on low-resistivity silicon. It was found that these structures exposed to illumination showed much lower noise than the full shot noise above 5 kHz under a certain operating condition. If the current noise power spectrum is expressed as S(ω) = 2eI<inf>p</inf>Γ<sup>2</sup>, where e is the electronic charge and I<inf>p</inf> is the photocurrent, the noise ratio Γ<sup>2</sup> lies between 0.2 and 1.0, depending on the bias voltage. These results are attributed to the planar structures of the samples having wide electrode separation. Spatially uniform carrier generation due to illumination at the active surface and the decrease in the cross-correlation between the current components in the structure might be playing the key role to reduce the noise to lower levels than that of full shot noise under a certain operating condition. © 2003 Elsevier Ltd. All rights reserved.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Observation of photoinduced shot noise in planar Mo/n-Si/Mo structures with undepleted region
    (2002-04-01)
    Niemcharoen, S.
    ;
    Ando, T.
    ;
    Supadech, S.
    ;
    Yasumura, Y.
    ;
    Sato, K.
    Measurements of low frequency shot noise due to photoinduced currents have been carried out on planar molybdenum/n-type silicon/molybdenum structures having long neutral region and Schottky barriers at both ends. Measurements were performed in the frequency range between 1 and 200 kHz at room temperature. The observed shot noise was found to be lower than the level of full shot noise. That is, when the current noise is expressed as S(ω) = 2qIΓ<sup>2</sup> (q, the electronic charge; I, the average current), the noise factor, Γ<sup>2</sup>, was estimated to be around 0.9, which is smaller than unity corresponding to so-called full shot noise. These results are attributed to the decay of autocorrelation effect in the current component photoinduced in the neutral region. © 2002 Elsevier Science Ltd. All rights reserved.