6533b862fe1ef96bd12c6e2a
RESEARCH PRODUCT
Electric field manipulation in Al/CdTe/Pt detectors under optical perturbations
Jan FrancLeonardo AbbeneV. DědičRoman GrillFabio PrincipatoA.a. Turturicisubject
Nuclear and High Energy Physics02 engineering and technology01 natural sciencesInduced polarizationlaw.inventionCdTe detectorX-ray and gamma ray spectroscopylawPolarizationElectric fieldElectric field0103 physical sciencesInstrumentationNuclear and High Energy Physic010302 applied physicsPhysicsbusiness.industrySettore FIS/01 - Fisica SperimentaleBiasing021001 nanoscience & nanotechnologySettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)Pockels effectAnodeWavelengthOptoelectronicsInfrared illumination0210 nano-technologybusinessPockels effectTunable laserLight-emitting diodedescription
Abstract Al/CdTe/Pt detectors are very attractive devices for high-resolution X-ray spectroscopy, even though they suffer from polarization phenomena, which cause a progressive time degradation of the spectroscopic performance. In this work we investigated on the time dependence of the electric field of an Al/CdTe/Pt detector under optical perturbation by means of Pockels effect measurements. A tunable laser with wavelengths ranging within 700−1000 nm and a 940 nm light emitting diode (LED) were used. The measurements of both the electric field profile and the total current were used to better understand the effects of the optical perturbation on polarization phenomena. The results point out as the above band-gap light, due to the trapping of photo-generated holes at the anode (the Al/CdTe blocking contact), brings to a reduction of the negative space charge caused by the bias voltage (bias induced polarization) and the LED irradiation (radiation induced polarization). The reduction of the negative space charge ensures a quite stable and uniform electric field distribution, typically termed depolarization. Conversely, optical perturbation with sub-band-gap light enhances the polarization with the formation of two oppositely charged regions within the detector.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2017-06-01 | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment |