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Vliv vnějších polí na elektrické pole a fotoproud detektorů CdTe / Influence of external fields on electric field and photocurrent in CdTe detectors

This thesis is focused on a study of CdTe and CdZnTe semiconductor detectors working under high flux of radiation. We studied experimentally an influence of high flux of X-rays and optical radiation on polarization of the detector. The polarization phenomenon decreases the efficiency of the detector due to a screening of an applied electric field by a space charge accumulated at deep levels due to a trapping of photogenerated carriers. In order to measure the electric field profiles in the detectors we employed a method based on cross polarizers technique and Pockels effect. The main objective of this work was to study the possibilities of an optical de-polarization of CdTe and CdZnTe detectors for different photon energies of additional light, its dynamics and physical origin. We have found that detectors can be de-polarized by above bandgap light. Moreover, CdZnTe detector can be depolarized by near infrared light and in a pulse mode. The de- polarization is associated with a compensation of the space charge at deep traps.

Identiferoai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:331712
Date January 2015
CreatorsRejhon, Martin
ContributorsFranc, Jan, Oswald, Jiří
Source SetsCzech ETDs
LanguageCzech
Detected LanguageEnglish
Typeinfo:eu-repo/semantics/masterThesis
Rightsinfo:eu-repo/semantics/restrictedAccess

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