Mapping of Large Area Cadmium Zinc Telluride (CZT) Wafers: Apparatus and Methods

1997 ◽  
Vol 487 ◽  
Author(s):  
B. A. Brunett ◽  
J. M. Van Scyoc ◽  
H. Yoon ◽  
T. S. Gilbert ◽  
T. E. Schlesinger ◽  
...  
Keyword(s):  
Transport Properties ◽  
Cadmium Zinc Telluride ◽  
Radiation Detector ◽  
Zinc Telluride ◽  
Hole Transport ◽  
Device Fabrication ◽  
Great Promise ◽  
Large Area ◽  
Detector Performance ◽  
Cadmium Zinc

AbstractCadmium Zinc Telluride (CZT) shows great promise as a semiconductor radiation detector material. CZT possesses advantageous material properties over other radiation detector materials in use today, such as a high intrinsic resistivity and a high cross-section for x and γ-rays. However, presently available CZT is not without limitations. The hole transport properties severely limit the performance of these detectors, and the yield of material possessing adequate electron transport properties is currently much lower than desired. The result of these material deficiencies is a lack of inexpensive CZT crystals of large volume for several radiation detector applications. One approach to help alleviate this problem is to measure the spatial distribution (or map) the electrical properties of large area CZT wafers prior to device fabrication. This mapping can accomplish two goals: identify regions of the wafers suitable for detector fabrication and correlate the distribution of crystalline defects with the detector performance. The results of this characterization can then be used by the crystal manufacturers to optimize their growth processes. In this work, we discuss the design and performance of apparatus for measuring the electrical characteristics of entire CZT wafers (up to 10 cm × 10 cm). The data acquisition and manipulation will be discussed and some typical data will be presented.

Mapping of Large Area Cadmium Zinc Telluride (CZT) Wafers: Apparatus and Methods

1997 ◽  
Vol 484 ◽  
Author(s):  
B. A. Brunett ◽  
J. M. Van Scyoc ◽  
H. Yoon ◽  
T. S. Gilbert ◽  
T. E. Schlesinger ◽  
...  
Keyword(s):  
Transport Properties ◽  
Cadmium Zinc Telluride ◽  
Radiation Detector ◽  
Zinc Telluride ◽  
Hole Transport ◽  
Device Fabrication ◽  
Great Promise ◽  
Large Area ◽  
Detector Performance ◽  
Cadmium Zinc

AbstractCadmium Zinc Telluride (CZT) shows great promise as a semiconductor radiation detector material. CZT possesses advantageous material properties over other radiation detector materials in use today, such as a high intrinsic resistivity and a high cross-section for x and γ-rays. However, presently available CZT is not without limitations. The hole transport properties severely limit the performance of these detectors, and the yield of material possessing adequate electron transport properties is currently much lower than desired. The result of these material deficiencies is a lack of inexpensive CZT crystals of large volume for several radiation detector applications. One approach to help alleviate this problem is to measure the spatial distribution (or map) the electrical properties of large area CZT wafers prior to device fabrication. This mapping can accomplish two goals: identify regions of the wafers suitable for detector fabrication and correlate the distribution of crystalline defects with the detector performance. The results of this characterization can then be used by the crystal manufacturers to optimize their growth processes. In this work, we discuss the design and performance of apparatus for measuring the electrical characteristics of entire CZT wafers (up to 10 cm × 10 cm). The data acquisition and manipulation will be discussed and some typical data will be presented.

scholarly journals Advances in CdZnTeSe for Radiation Detector Applications

Radiation ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 123-130
Author(s):  
Utpal N. Roy ◽  
Giuseppe S. Camarda ◽  
Yonggang Cui ◽  
Ralph B. James
Keyword(s):  
Grain Boundary ◽  
Cadmium Zinc Telluride ◽  
Radiation Detector ◽  
Zinc Telluride ◽  
High Energy ◽  
Detector Performance ◽  
Wide Range ◽  
Temperature Detector ◽  
Te Inclusions ◽  
Cadmium Zinc

Detection of X- and gamma-rays is essential to a wide range of applications from medical imaging to high energy physics, astronomy, and homeland security. Cadmium zinc telluride (CZT) is the most widely used material for room-temperature detector applications and has been fulfilling the requirements for growing detection demands over the last three decades. However, CZT still suffers from the presence of a high density of performance-limiting defects, such as sub-grain boundary networks and Te inclusions. Cadmium zinc telluride selenide (CZTS) is an emerging material with compelling properties that mitigate some of the long-standing issues seen in CZT. This new quaternary is free from sub-grain boundary networks and possesses very few Te inclusions. In addition, the material offers a high degree of compositional homogeneity. The advancement of CZTS has accelerated through investigations of the material properties and virtual Frisch-grid (VFG) detector performance. The excellent material quality with highly reduced performance-limiting defects elevates the importance of CZTS as a potential replacement to CZT at a substantially lower cost.

Cadmium zinc telluride and its use as a nuclear radiation detector material

2001 ◽  
Vol 32 (4-5) ◽  
pp. 103-189 ◽  
Author(s):  
T.E Schlesinger ◽  
J.E Toney ◽  
H Yoon ◽  
E.Y Lee ◽  
B.A Brunett ◽  
...  
Keyword(s):  
Cadmium Zinc Telluride ◽  
Radiation Detector ◽  
Zinc Telluride ◽  
Nuclear Radiation ◽  
Nuclear Radiation Detector ◽  
Cadmium Zinc ◽  
Detector Material

Thermal Annealing: A Technique to Improve the Performance of Cadmium Zinc Telluride (CZT) Material for Semiconductor Radiation Detector Applications

2012 ◽  
Author(s):  
Aaron L. Adams ◽  
Aschalew Kassu ◽  
Wing Chan ◽  
Mebougna Drabo ◽  
Rodney Pinder ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Thermal Annealing ◽  
Large Volume ◽  
Cadmium Zinc Telluride ◽  
Radiation Detector ◽  
Zinc Telluride ◽  
Radiation Detectors ◽  
Nuclear Radiation ◽  
Structural Defects ◽  
Cadmium Zinc

Extensive research was undertaken over the past 20 years to investigate the suitability of cadmium zinc telluride (CZT) crystals as a material for room-temperature nuclear-radiation detectors. Large-volume CZT crystals, with thicknesses up to 2 cm and large effective areas of roughly 5–10 cm2, are needed to fabricate efficient detectors that meet the working requirements of federal agencies, such as the DOE/NNSA (Department Energy National Nuclear Security Administration), Department of Homeland Security (DHS), and the Department of Defense (DOD). However, because of the imperfect methods for growing crystals, the resulting large-volume crystals most often are not perfect single ones, and contain structural defects such as voids, pipes, impurities from source materials, tellurium inclusions and precipitates, vacancies, and vacancy-impurity complexes generated during the process of their production. Other extended defects that may be present include grain boundaries, micro twins, and walls of dislocations (sub-grain boundaries). Identifying these defects, controlling their occurrence and eliminating them from the bulk CZT material currently are important tasks that will improve the yield of detector-grade crystals from ingots, and ultimately better their performance. In this study, we used a post-growth thermal annealing technique to remove the performance-limiting defects caused by tellurium inclusions and associated impurities in the CZT crystals. We realized a 66% ± 16% reduction in the size of the inclusions, with an overall elimination of 17% ± 2% of them. We believe that our experimental results offer a better understanding of the optimal annealing parameters, and of the dynamic properties of post-growth annealing processes.

Detector performance crystallinity and impurity study of cadmium zinc telluride crystals grown from the melt

2001 ◽  
Author(s):  
Haim Hermon ◽  
Michael M. Schieber ◽  
M. Factor ◽  
Tuviah E. Schlesinger ◽  
Ralph B. James ◽  
...  
Keyword(s):  
Cadmium Zinc Telluride ◽  
Zinc Telluride ◽  
Detector Performance ◽  
Cadmium Zinc

Study of impurity segregation, crystallinity, and detector performance of melt-grown cadmium zinc telluride crystals

2002 ◽  
Vol 237-239 ◽  
pp. 2082-2090 ◽  
Author(s):  
M. Schieber ◽  
T.E. Schlesinger ◽  
R.B. James ◽  
H. Hermon ◽  
H. Yoon ◽  
...  
Keyword(s):  
Cadmium Zinc Telluride ◽  
Zinc Telluride ◽  
Detector Performance ◽  
Impurity Segregation ◽  
Cadmium Zinc

Extracting Trap Parameters From Picts Spectra In Cadmium Zinc Telluride Radiation Detector Material

1997 ◽  
Vol 487 ◽  
Author(s):  
J. E. Toney ◽  
B. A. Brunett ◽  
T. E. Schlesinger ◽  
R. B. James
Keyword(s):  
Regularization Method ◽  
Electroless Deposition ◽  
Cadmium Zinc Telluride ◽  
Radiation Detector ◽  
Zinc Telluride ◽  
Small Component ◽  
Infrared Excitation ◽  
Electron And Hole Traps ◽  
Cadmium Zinc ◽  
Detector Material

AbstractWe demonstrate that the regularization method due to Weese can resolve closely-spaced peaks in PICTS spectra for cadmium zinc telluride. We also show that electron and hole traps can be distinguished from each other by the bias dependence of the spectrum when using an excitation source that is primarily infrared but which contains a small component of visible light. Lastly we show that there are qualitative differences between PICTS spectra taken with infrared excitation and those taken with visible excitation. We attribute the surface-related levels to diffusion into the detector material of gold from electroless deposition of contacts.

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