Optical Studies of the Internal Electric Field Distributions of CdZnTe Detectors Under Bias Conditions

1997 ◽  
Vol 487 ◽  
Author(s):  
H. W. Yao ◽  
R. J. Anderson ◽  
R. B. James ◽  
R. W. Olsen
Keyword(s):  
Electric Field ◽  
Radiation Detector ◽  
Radiation Detectors ◽  
Uniform Electric Field ◽  
Internal Electric Field ◽  
Field Distributions ◽  
Intensity Changes ◽  
Temperature Radiation ◽  
Cdznte Detectors ◽  
Czt Detectors

AbstractThe internal electric field distributions of the CdZnTe (CZT) detectors under bias were characterized by optical polarized transmission at a 952 nm illumination utilizing the Pockels electro-optic effect. Two-dimensional (2D) images mapping the internal electrical field intensity changes were obtained to study the performance of CZT room-temperature radiation detectors. Planar and a P-I-N structured CZT detectors were investigated under different operating bias voltages. Analysis of optical profiles from a planar single crystal detector provides a quantitative nondestructive description of the electric field or voltage distributions inside a radiation detector. The P-I-N structured CZT detector showed a nearly uniform electric field in a width which varied with the operating bias voltage. An energyband model of a semiconductor junction with a depletion layer was employed to understand the results.

Negative Capacitance Phenomena in CZT Room Temperature Radiation Detectors

2005 ◽  
Vol 480-481 ◽  
pp. 399-404
Author(s):  
Mahmoud A. Hassan
Keyword(s):  
Bias Voltage ◽  
Room Temperature ◽  
Bulk Material ◽  
Radiation Detector ◽  
Radiation Detectors ◽  
Negative Capacitance ◽  
Low Frequencies ◽  
Temperature Radiation ◽  
Czt Detectors ◽  
Small Voltage

CdZnTe , Cadmium zinc telluride (CZT) is an interesting room temperature radiation detector. This research paper is reporting a negative capacitance behavior of CZT detectors at bias voltages around 60V. Initially at 0V, the CZT capacitance is positive and decreases with bias voltage increase. At around 60V, the measured capacitance approaches zero, then with small voltage increase , capacitance value reverses sign and starts to increase in the negative direction with increasing bias voltage . This effect is stable at 100 kHz. The behavior of low and other quality detectors can differ, low quality detectors can show negative capacitance at low bias voltages and low frequencies. The initial explanation of this phenomena is due to non-uniform distribution of impurities inside the bulk material.

Mapping Detector Response Over the Area of a CdZnTe-Multiple-Electrode Detector

1997 ◽  
Vol 484 ◽  
Author(s):  
C. L. Lingren ◽  
B. Apotovsky ◽  
J. F. Butler ◽  
F. P. Doty ◽  
S. J. Friesenhahn ◽  
...  
Keyword(s):  
Electric Field ◽  
Room Temperature ◽  
Gamma Ray ◽  
Radiation Detectors ◽  
Uniform Electric Field ◽  
Detector Response ◽  
Hole Trapping ◽  
Temperature Radiation ◽  
Multiple Electrode

AbstractSemiconductor multiple-electrode detectors have been developed for the purpose of reducing effects of hole trapping in room-temperature radiation detectors.1,2 Some reported geometries maintain a nearly-uniform electric field inside the detector, but others generate an electric field that is very non-uniform and highly-concentrated at the anode. This paper reports the results of mapping such a detector (having a non-uniform electric field) with a finely collimated gamma-ray beam to determine the detector response as a function of position.

Mapping Detector Response Over the Area of a CdZnTe-Multiple-Electrode Detector

1997 ◽  
Vol 487 ◽  
Author(s):  
C. L. Lingren ◽  
B. Apotovsky ◽  
J. F. Butler ◽  
F. P. Doty ◽  
S. J. Friesenhahn ◽  
...  
Keyword(s):  
Electric Field ◽  
Room Temperature ◽  
Gamma Ray ◽  
Radiation Detectors ◽  
Uniform Electric Field ◽  
Detector Response ◽  
Hole Trapping ◽  
Temperature Radiation ◽  
Multiple Electrode

AbstractSemiconductor multiple-electrode detectors have been developed for the purpose of reducing effects of hole trapping in room-temperature radiation detectors. Some reported geometries maintain a nearly-uniform electric field inside the detector, but others generate an electric field that is very non-uniform and highly-concentrated at the anode. This paper reports the results of mapping such a detector (having a non-uniform electric field) with a finely collimated gamma-ray beam to determine the detector response as a function of position.

A New Method to Improve Internal Electric Field Distributions of Pockels OVS

2017 ◽  
Vol 17 (13) ◽  
pp. 4115-4121 ◽  
Author(s):  
Qiao Tan ◽  
Qifeng Xu ◽  
Linyang Chen ◽  
Yifan Huang
Keyword(s):  
Electric Field ◽  
New Method ◽  
Internal Electric Field ◽  
Field Distributions

Studies of Charge Collection in GaAs Radiation Detectors

1993 ◽  
Vol 302 ◽  
Author(s):  
K Berwick ◽  
M R Brozel ◽  
C M Butiar ◽  
M Cowperthwaite ◽  
Y Hou
Keyword(s):  
Electric Field ◽  
Collection Efficiency ◽  
Radiation Detectors ◽  
Alpha Particles ◽  
Uniform Electric Field ◽  
Charge Collection ◽  
Applied Bias ◽  
Particle Detectors ◽  
Charge Collection Efficiency ◽  
Lec Gaas

ABSTRACTThe behaviour of the charge collection efficiency of particle detectors fabricated from Semi-Insulating (SI) Liquid Encapsulated Czochralski (LEC) GaAs as a function of applied bias is investigated for alpha particles and it is shown that it cannot be explained by simple models that assume a uniform electric field across the detector. To investigate this the electric field within the SI GaAs has been studied. We have attempted to correlate the measured charge collection efficiency with the observed field distributions. Some correlation is found but other effects may also be present.

scholarly journals Opto-electrical characterization and X-ray Mapping of large-volume cadmium zinc telluride radiation detectors

2009 ◽  
Vol 1164 ◽  
Author(s):  
Ge Yang ◽  
Aleksey E Bolotnik ◽  
Giuseppe Camarda ◽  
Yonggang Cui ◽  
Anwar Hossain ◽  
...  
Keyword(s):  
Large Volume ◽  
Cadmium Zinc Telluride ◽  
Radiation Detection ◽  
Zinc Telluride ◽  
Radiation Detectors ◽  
Internal Electric Field ◽  
Pockels Effect ◽  
X Ray ◽  
Czt Detectors ◽  
Cadmium Zinc

AbstractLarge-volume cadmium zinc telluride (CZT) radiation detectors would greatly improve radiation detection capabilities and, therefore, attract extensive scientific and commercial interests. CZT crystals with volumes as large as hundreds of centimeters can be achieved today due to improvements in the crystal growth technology. However, the poor performance of large-volume CZT detectors is still a challenging problem affecting the commercialization of CZT detectors and imaging arrays. We have employed Pockels effect measurements and synchrotron X-ray mapping techniques to investigate the performance-limiting factors for large-volume CZT detectors. Experimental results with the above characterization methods reveal the non-uniform distribution of internal electric field of large-volume CZT detectors, which help us to better understand the responsible mechanism for the insufficient carrier collection in large-volume CZT detectors.

Purification of HgI2 Crystals from Physical Vapor Transport for Application as Radiation Detectors

2012 ◽  
Vol 586 ◽  
pp. 156-160 ◽  
Author(s):  
João F. Trencher Martins ◽  
Robinson A. dos Santos ◽  
Fabio E. da Costa ◽  
Carlos H. de Mesquita ◽  
Margarida M. Hamada
Keyword(s):  
Impurity Concentration ◽  
Radiation Detector ◽  
Radiation Detectors ◽  
Vapor Transport ◽  
Future Application ◽  
Physical Vapor Transport ◽  
Semiconductor Detectors ◽  
Trace Impurities ◽  
Detector Performance ◽  
Temperature Radiation

The establishment of a technique for mercury iodide (HgI2) purification and crystal growth is described, aiming this crystal future application as room temperature radiation semiconductor detectors. Repeated Physical Vapor Transport (PVT) technique was studied for purification and growth of the crystal. To evaluate the purification efficiency, measurements of the impurity concentration were made after each growth, analyzing the trace impurities. A significant decrease of the impurity concentration, resulting from the purification number, was observed. A significant improvement in the HgI2 radiation detector performance was achieved for purer crystals, growing the crystal twice by the PVT technique.

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