Publication detail

Low Frequency Noise of the CdTe Crystals

GRMELA, L. ŠIKULA, J. ZAJAČEK, J. MORAVEC, P.

Original Title

Low Frequency Noise of the CdTe Crystals

Czech Title

Nízkofrekvenční šum v krystalech CdTe

English Title

Low Frequency Noise of the CdTe Crystals

Type

conference paper

Language

en

Original Abstract

Experimental studies of transport and noise characteristics of CdTe bulk single crystals have been carried out. The noise measurement was used to characterized the quality of sample surface and contact technology. As a quality indicator we have choose the 1/f noise. In this case the 1/f noise is generated in sample volume, on surface and contacts. The main problem to be solved was the separation of these noise sources. The noise spectral density was measured by four probe method to separate contact noise from the other sources. To distinguish between 1/f noise generated in sample volume and on the surface the noise measurement was performed as a function of incident light wavelengths for constant electric field and current was varied both by the sample illumination and photon energy change. There are three different 1/f noise sources: bulk 1/f noise generated by sub band gap energy photons with current noise spectral density proportional to first power of current, surface 1/f noise generated by over band gap energy photons with current noise spectral density proportional to second power of current, contact 1/f noise with current noise spectral density proportional to higher than second power of current. Experimental results are used to distinguish between McWhorter model in which 1/f type noise is a result of mobile carrier number fluctuations and Hooge model, which explains 1/f noise as mobility fluctuations. The additivity of GR spectra proposed by McWhorter is a serious problem. There is experimental proof that in high-quality samples with low surface recombination the 1/f noise is a fluctuation in the mobility.

Czech abstract

Článek pojednává o experimentálním studiu transportu a šumových charakteristik v objemu krastalů CdTe. Šumové charakteristiky jsou mírou kvality povrchu vzorků a jejich kontaktů. Jako indikátor spolehlivosti jsme vybrali 1/f šum, který vzniká v objemu a na kontaktech. Hlavní problém je ve zjišťování příspěvku těchto zdrojů do celké úrovně 1/f šumu.

English abstract

Experimental studies of transport and noise characteristics of CdTe bulk single crystals have been carried out. The noise measurement was used to characterized the quality of sample surface and contact technology. As a quality indicator we have choose the 1/f noise. In this case the 1/f noise is generated in sample volume, on surface and contacts. The main problem to be solved was the separation of these noise sources. The noise spectral density was measured by four probe method to separate contact noise from the other sources. To distinguish between 1/f noise generated in sample volume and on the surface the noise measurement was performed as a function of incident light wavelengths for constant electric field and current was varied both by the sample illumination and photon energy change. There are three different 1/f noise sources: bulk 1/f noise generated by sub band gap energy photons with current noise spectral density proportional to first power of current, surface 1/f noise generated by over band gap energy photons with current noise spectral density proportional to second power of current, contact 1/f noise with current noise spectral density proportional to higher than second power of current. Experimental results are used to distinguish between McWhorter model in which 1/f type noise is a result of mobile carrier number fluctuations and Hooge model, which explains 1/f noise as mobility fluctuations. The additivity of GR spectra proposed by McWhorter is a serious problem. There is experimental proof that in high-quality samples with low surface recombination the 1/f noise is a fluctuation in the mobility.

Keywords

CdTe crystal, low frequency noise

RIV year

2005

Released

19.09.2005

Publisher

American Institute of Physics

Location

Melville, USA

ISBN

0-7354-0267-1

Book

Noise and Fluctuations

Pages from

175

Pages to

178

Pages count

4

BibTex


@inproceedings{BUT15480,
  author="Lubomír {Grmela} and Josef {Šikula} and Jiří {Zajaček} and Pavel {Moravec}",
  title="Low Frequency Noise of the CdTe Crystals",
  annote="Experimental studies of transport and noise characteristics of CdTe bulk single crystals have been carried out. The noise measurement was used to characterized the quality of sample surface and contact technology. As a quality indicator we have choose the 1/f noise. In this case the 1/f noise is generated in sample volume, on surface and contacts. The main problem to be solved was the separation of these noise sources. The noise spectral density was measured by four probe method to separate contact noise from the other sources. To distinguish between 1/f noise generated in sample volume and on the surface the noise measurement was performed as a function of incident light wavelengths for constant electric field and current was varied both by the sample illumination and photon energy change. There are three different 1/f noise sources: bulk 1/f noise generated by sub band gap energy photons with current noise spectral density proportional to first power of current, surface 1/f noise generated by over band gap energy photons with current noise spectral density proportional to second power of current, contact 1/f noise with current noise spectral density proportional to higher than second power of current. Experimental results are used to distinguish between McWhorter model in which 1/f type noise is a result of mobile carrier number fluctuations and Hooge model, which explains 1/f noise as mobility fluctuations. The additivity of GR spectra proposed by McWhorter is a serious problem. There is experimental proof that in high-quality samples with low surface recombination the 1/f noise is a fluctuation in the mobility.",
  address="American Institute of Physics",
  booktitle="Noise and Fluctuations",
  chapter="15480",
  institution="American Institute of Physics",
  year="2005",
  month="september",
  pages="175--178",
  publisher="American Institute of Physics",
  type="conference paper"
}