Publication detail

Study of Electric Field Distribution and Low Frequency Noise of CdZnTe Radiation Detectors

ŠIK, O. GRMELA, L. ELHADIDY, H. DĚDIČ, V. ŠIKULA, J. GRMELA, P. FRANC, J. ŠKARVADA, P. HOLCMAN, V.

Original Title

Study of Electric Field Distribution and Low Frequency Noise of CdZnTe Radiation Detectors

Czech Title

Study of Electric Field Distribution and Low Frequency Noise of CdZnTe Radiation Detectors Studie rozložení elektrického pole a nízkofrekvenčního Studie rozložení elektrického pole a šumu u CdTe detektorů ionizujícího záření

English Title

Study of Electric Field Distribution and Low Frequency Noise of CdZnTe Radiation Detectors

Type

journal article

Language

en

Original Abstract

Polarization phenomena in a metal-semiconductor-metal (M-S-M) structure of metallic Schottky contacts deposited on CdZnTe radiation detectors were studied. We evaluate the distribution of the electric field along the biased M-S-M structure by Pockels measurements. The results show that almost all the electric field is developed across the depletion layer of the reverse-biased contact. The noise measurements of the CdZnTe detectors studied show that the dominant noise is 1/f m noise. The 1/f m noise, with parameter m close to unity, is present at frequencies bellow 100 Hz and its bandwidth decreases in the course of the polarization process. At higher frequencies, we observed an increase of the m parameter to 2, which indicates a strengthened effect of generation-recombination processes. In the frequency band of dominating 1/f m = 1 noise, the increase of magnitude of noise spectral density was proportional to the power of 6, in relation to current through the detector. This high value is explained as a result of a screening effect of the space charge buildup during the polarization

Czech abstract

Šlánek je zaměřen na analýzu lolerizačního eektu u kovových Schottkyho kotaktů detektorů ionizujícíh záření na bázi CdTe. Vyhodnocení distribuce el. pole ve vzotku probíhalo na základě měření Pockelsova jevu. Výsledky ukazují na to, že takřka celé el. pole se uplatňuje ve vyprázdněné oblasti závěrně pólovaného kontaktu. Měření spekttrální hustoty aditivního šumu detektoru poukázalo na to, že dominantním typem šumu je šum typu 1/f. Směrnice spektrální hustoty je blízká teoretické hodnotě 1 ve frekvenčních oblastech pod 100 Hz. Pásmo s dominujícím šumem typu 1/f se směrnicí 1 se zužuje v průběhu polarizace. Ve vyšších frekvencích byl pozorován výraznější vliv generačně - rekombinačních procesů. Spektrální hustota šumu 1/f se směrnicí 1 prostl s expnentem 6 při zvyšujícím se proudu. Tento velmi výrazný rozdíl oproti teoretické hodnotě 2 si lze vysvětlit tím, že se jedná o následek stínícího efektu prostorového náboje, který vzniká v průběhu polarizace detektoru.

English abstract

Polarization phenomena in a metal-semiconductor-metal (M-S-M) structure of metallic Schottky contacts deposited on CdZnTe radiation detectors were studied. We evaluate the distribution of the electric field along the biased M-S-M structure by Pockels measurements. The results show that almost all the electric field is developed across the depletion layer of the reverse-biased contact. The noise measurements of the CdZnTe detectors studied show that the dominant noise is 1/f m noise. The 1/f m noise, with parameter m close to unity, is present at frequencies bellow 100 Hz and its bandwidth decreases in the course of the polarization process. At higher frequencies, we observed an increase of the m parameter to 2, which indicates a strengthened effect of generation-recombination processes. In the frequency band of dominating 1/f m = 1 noise, the increase of magnitude of noise spectral density was proportional to the power of 6, in relation to current through the detector. This high value is explained as a result of a screening effect of the space charge buildup during the polarization

Keywords

Gamma detectors, CdTe. Polarization, Pockels Effect, Noise

RIV year

2013

Released

06.06.2013

Publisher

IOP

Location

London, Great Britain

Pages from

1

Pages to

6

Pages count

6

URL

BibTex


@article{BUT99274,
  author="Ondřej {Šik} and Lubomír {Grmela} and Hassan Ali Mohamed {Elhadidy} and Václav {Dědič} and Josef {Šikula} and Petr {Grmela} and Jan {Franc} and Pavel {Škarvada} and Vladimír {Holcman}",
  title="Study of Electric Field Distribution and Low Frequency Noise of CdZnTe Radiation Detectors",
  annote="Polarization phenomena in a metal-semiconductor-metal (M-S-M) structure of metallic Schottky contacts deposited on CdZnTe radiation detectors were studied. We evaluate the distribution of the electric field along the biased M-S-M structure by Pockels measurements. The results show that almost all the electric field is developed across the depletion layer of the reverse-biased contact. The noise measurements of the CdZnTe detectors studied show that the dominant noise is 1/f m noise. The 1/f m noise, with parameter m close to unity, is present at frequencies bellow 100 Hz and its bandwidth decreases in the course of the polarization process. At higher frequencies, we observed an increase of the m parameter to 2, which indicates a strengthened effect of generation-recombination processes. In the frequency band of dominating 1/f m = 1 noise, the increase of magnitude of noise spectral density was proportional to the power of 6, in relation to current through the detector. This high value is explained as a result of a screening effect of the space charge buildup during the polarization",
  address="IOP",
  chapter="99274",
  doi="10.1088/1748-0221/8/06/C06005",
  institution="IOP",
  number="23",
  volume="6",
  year="2013",
  month="june",
  pages="1--6",
  publisher="IOP",
  type="journal article"
}