Publication detail

Metal-Semiconductor Junction Role in CdTe Detectors

GRMELA, L. ŠIK, O.

Original Title

Metal-Semiconductor Junction Role in CdTe Detectors

Czech Title

Chováni heterostruktury polovodič-kov u detektorů ionizujícího záření na bázi CdTe

English Title

Metal-Semiconductor Junction Role in CdTe Detectors

Type

journal article

Language

en

Original Abstract

We have performed noise spectroscopy and charge transport properties analysis of CdTe detectors. Two types of high volume detectors are compared: Low ohmic (based on low resistivity crystal material 70 Ohm cm) and semi-insulating ( 10^8 Ohmcm).The theoretical fundaments of contacts role in detector system are given. We observed high asymmetry of IV characteristics of the lowohmic sample between normal and reverse bias, showing improper quality of contacts preparation, caused by higher concentration of impurities in metal-semiconductor area. This finding is supported by the fact that the low frequency noise spectral density is proportional to applied voltage with exponent 2.7, which is higher than the theoretical value 2.The semi-insulating sample very good contact rectification effect symmetry and less additive noise to the detector system.

Czech abstract

Ve článku je popsána teoretická báze chování kontaktů v detektrorovém systému. Byla provedena analýza transportních charakteristik a šumová spektroskopie detektotů ionizujícího záření na bázi CdTe (nízkoohmického: krystal s měrnou vodivostí 70 Ohm cm a semiizolačního 10^8 Ohm cm). U nízkoohmického vzorku jsme pozorovali výraznou asymetrii VA charakteristik pro každý kontakt. To poukazuje na rozdílnou kvalitu přípravy kontaktů, která se projevila vyšší koncentrací defektů v oblasti přechodu polovodič-kov. Toto zjištění je potvrzeno nárůstem PSD šumového signálu s exponentem 2,7 se vzrůstajícím napětím, což je hodnota vyšší než teoretická(2). Vzorek vyrobený ze semiizolačního materiálu vykazoval výraznou symetrii křivek VA charakteristik a jeho kontakty dosahovaly vysoké blokační účinnosti. Navíc, tento detektor vyazoval nízkou hladinu aditivního šumu.

English abstract

We have performed noise spectroscopy and charge transport properties analysis of CdTe detectors. Two types of high volume detectors are compared: Low ohmic (based on low resistivity crystal material 70 Ohm cm) and semi-insulating ( 10^8 Ohmcm).The theoretical fundaments of contacts role in detector system are given. We observed high asymmetry of IV characteristics of the lowohmic sample between normal and reverse bias, showing improper quality of contacts preparation, caused by higher concentration of impurities in metal-semiconductor area. This finding is supported by the fact that the low frequency noise spectral density is proportional to applied voltage with exponent 2.7, which is higher than the theoretical value 2.The semi-insulating sample very good contact rectification effect symmetry and less additive noise to the detector system.

Keywords

CdTe, transport characteristics, noise, contact quality

RIV year

2013

Released

12.06.2013

Publisher

Versita Publishing

Location

Warsaw, Poland

Pages from

22

Pages to

25

Pages count

4

URL

BibTex


@article{BUT100283,
  author="Lubomír {Grmela} and Ondřej {Šik}",
  title="Metal-Semiconductor Junction Role in CdTe Detectors",
  annote="We have performed noise spectroscopy and charge transport properties analysis of CdTe detectors. Two types of high volume detectors are compared: Low ohmic (based on low resistivity crystal material  70 Ohm cm) and semi-insulating ( 10^8 Ohmcm).The theoretical fundaments of contacts role in detector system are given. We observed high asymmetry of IV characteristics of the lowohmic sample between normal and reverse bias, showing improper quality of contacts preparation, caused by higher concentration of impurities in metal-semiconductor area. This finding is supported by the fact that the low frequency noise spectral density is proportional to applied voltage with exponent 2.7, which is higher than the theoretical value 2.The semi-insulating sample very good contact rectification effect symmetry and less additive noise to the detector system.",
  address="Versita Publishing",
  chapter="100283",
  doi="10.2478/aeei-2013-0004",
  institution="Versita Publishing",
  number="1",
  volume="13",
  year="2013",
  month="june",
  pages="22--25",
  publisher="Versita Publishing",
  type="journal article"
}