Cadmium Telluride X-ray pad detectors with different passivation dielectrics

Gädda, A.; Ott, J.; Karadzhinova-Ferrer, A.; Golovleva, M.; Kalliokoski, Matti; Winkler, Alexander; Luukka, P.; Härkönen, J.

doi:10.1016/j.nima.2018.08.063

Cited by 8 publications

(5 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All metallized detectors are 1 mm thick in a planar electrode configuration. The sample containing Al 2 O 3 has an optical opening of 2 mm wide diameter, surrounded by 20 nm thick TiW [11]. The optical opening was created in order to study charge transport on the dielectric itself.…”

Section: Materials Preparationmentioning

confidence: 99%

Analysis and characterization of CdTe material surface defects

Bezak

Bharthuar²,

Brücken³

et al. 2023

J. Inst.

Self Cite

View full text Add to dashboard Cite

To study the impact of various defects associated close to the surface layer of CdTe material, we use scanning laser Transient Current Technique. This gives us an overview of different compositional inhomogeneities, such as dislocations, grain boundaries, and tellurium inclusions. Particularly, reconstructed high resolution spatial images provide a map of different electrically active defects. Each spatial point contains a recording of a current pulse, from which shape we calculate drift times and total collected charge. Charge mobility and charge loss are extracted from current pulses and show the effects of charge trapping and polarization. In addition, we investigate the impact of the ALD alumina-CdTe interface and negative fixed charge trapping using both passivated and non-passivated CdTe crystals.

show abstract

Section: Materials Preparationmentioning

confidence: 99%

Analysis and characterization of CdTe material surface defects

Bezak

Bharthuar²,

Brücken³

et al. 2023

J. Inst.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The CdTe pad detectors discussed in this paper represent a simple structure of a CdTe single crystal with metal electrodes on both sides. Prior to metallization, CdTe was passivated with aluminium nitride (AlN) [15,18]. The contacts for both sides of CdTe detector were formed by sputtering depositions resulting in Schottky barrier contacts.…”

Section: Tct Measurementsmentioning

confidence: 99%

Modeling the impact of defects on the charge collection efficiency of a Cadmium Telluride detector

Golovleva¹,

Bezak²,

Bharthuar³

et al. 2021

J. Inst.

View full text Add to dashboard Cite

Cadmium telluride is a favorable material for X-ray detection as it has an outstanding characteristic for room temperature operation. It is a high-Z material with excellent photon radiation absorption properties. However, CdTe single crystals may include a large number of extended crystallographic defects, such as grain boundaries, twins, and tellurium (Te) inclusions, which can have an impact on detector performance. A Technology Computer Aided Design (TCAD) local defect model has been developed to investigate the effects of local defects on charge collection efficiency (CCE). We studied a 1 mm thick Schottky-type CdTe radiation detector with transient-current technique by using a red laser at room temperature. By raster scanning the detector surface we were able to study signal shaping within the bulk, and to locate surface defects by observing their impact on the CCE. In this paper we present our TCAD model with localized defect, and compare the simulation results to TCT measurements. In the model an inclusion with a diameter of 10 μm was assumed. The center of the defect was positioned at 6 μm distance from the surface. We show that the defect has a notable effect on current transients, which in turn affect the CCE of the CdTe detector. The simulated charge collection at the position of the defect decreases by 80 % in comparison to the defect-free case. The simulations show that the defects give a characteristic shape to TCT signal. This can further be used to detect defects in CdTe detectors and to estimate the overall defect density in the material.

show abstract

“…Also CdTe has high mobility-lifetime product (μτ). Thus CdTe is a very attractive material for X-and γ-radiation detection with many advantages over other semiconductors [13,14]. According to the Shockley-Quessier limit [15], the maximum power conversion efficiency (PCE) of cadmium telluride is up to 32 %, which is a promising material for photovoltaic applications.…”

Section: Introductionmentioning

confidence: 99%

Electron, phonon, optical and thermodynamic properties of CdTe crystal calculated by DFT

Ільчук

Nykyruy

Kashuba

et al. 2022

Phys. Chem. Solid St.

View full text Add to dashboard Cite

Electronic and phonon band structure, thermodynamic and optical properties are studied for the CdTe crystal. We calculated the electron and phonon dispersion at high symmetry directions, density of electron and phonon state, temperature dependence feature of Raman spectra, heat capacity, free energy, entropy, enthalpy and Debay temperature estimated with the generalized gradient approximation (GGA). A Perdew–Burke–Ernzerhof functional (PBE) was utilized. To study the optical properties was use a complex dielectric function ε(ħω). All of the calculated parameters correlate well with the known experimental data.

show abstract

Cadmium Telluride X-ray pad detectors with different passivation dielectrics

Cited by 8 publications

References 23 publications

Analysis and characterization of CdTe material surface defects

Analysis and characterization of CdTe material surface defects

Modeling the impact of defects on the charge collection efficiency of a Cadmium Telluride detector

Electron, phonon, optical and thermodynamic properties of CdTe crystal calculated by DFT

Contact Info

Product

Resources

About