Signal generation in CdZnTe strip detectors

Hamel, L. A.; Macri, J.; Stahle, C. M.; Odom, J.; Birsa, F.; Shu, P.; Doty, F. Patrick

doi:10.1109/23.507077

Cited by 29 publications

(7 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, the so called "small pixel effect" allows for improvement of the tailing effect when the pixel size of the detector is much smaller than the thickness of CZT. 24,28 However, small pixel size results in charge sharing between pixels. Charge sharing, in turn, deteriorates spectral shape.…”

Section: Discussionmentioning

confidence: 99%

CZT detectors used in different irradiation geometries: Simulations and experimental results

Fritz

Shikhaliev

2009

Medical Physics

View full text Add to dashboard Cite

The purpose of this work was to evaluate potential advantages and limitations of CZT detectors used in surface-on, edge-on, and tilted angle irradiation geometries. Simulations and experimental investigations of the energy spectrum measured by a CZT detector have been performed using different irradiation geometries of the CZT. Experiments were performed using a CZT detector with 10 x 10 mm2 size and 3 mm thickness. The detector was irradiated with collimated photon beams from Am-241 (59.5 keV) and Co-57 (122 keV). The edge-scan method was used to measure the detector response function in edge-on illumination mode. The tilted angle mode was investigated with the radiation beam directed to the detector surface at angles of 90 degrees, 15 degrees, and 10 degrees. The Hecht formalism was used to simulate theoretical energy spectra. The parameters used for simulations were matched to experiment to compare experimental and theoretical results. The tilted angle CZT detector suppressed the tailing of the spectrum and provided an increase in peak-to-total ratio from 38% at 90 degrees to 83% at 10 degrees tilt angle for 122 keV radiation. The corresponding increase for 59 keV radiation was from 60% at 90 degrees to 85% at 10 degrees tilt angle. The edge-on CZT detector provided high energy resolution when the beam thickness was much smaller than the thickness of CZT. The FWHM resolution in edge-on illumination mode was 4.2% for 122 keV beam with 0.3 mm thickness, and rapidly deteriorated when the thickness of the beam was increased. The energy resolution of surface-on geometry suffered from strong tailing effect at photon energies higher than 60 keV. It is concluded that tilted angle CZT provides high energy resolution but it is limited to a 1D linear array configuration. The surface-on CZT provides 2D pixel arrays but suffers from tailing effect and charge build up. The edge-on CZT is considered suboptimal as it requires small beam thickness and also suffers from charge buildup.

show abstract

Section: Discussionmentioning

confidence: 99%

CZT detectors used in different irradiation geometries: Simulations and experimental results

Fritz

Shikhaliev

2009

Medical Physics

View full text Add to dashboard Cite

show abstract

“…A research group at the University of New Hampshire Space Science Center developed the earliest prototype of CdZnTe strip detector [62–64]. This device was designed using a monolithic CdZnTe substrate with orthogonal strips on each surface, so that a “pixel” is generated in the overlapping area of two cross orthogonal strips.…”

Section: Unipolar Detectors Of Different Anode Geometriesmentioning

confidence: 99%

Progress in the Development of CdZnTe Unipolar Detectors for Different Anode Geometries and Data Corrections

Zhang

et al. 2013

Sensors

View full text Add to dashboard Cite

CdZnTe detectors have been under development for the past two decades, providing good stopping power for gamma rays, lightweight camera heads and improved energy resolution. However, the performance of this type of detector is limited primarily by incomplete charge collection problems resulting from charge carriers trapping. This paper is a review of the progress in the development of CdZnTe unipolar detectors with some data correction techniques for improving performance of the detectors. We will first briefly review the relevant theories. Thereafter, two aspects of the techniques for overcoming the hole trapping issue are summarized, including irradiation direction configuration and pulse shape correction methods. CdZnTe detectors of different geometries are discussed in detail, covering the principal of the electrode geometry design, the design and performance characteristics, some detector prototypes development and special correction techniques to improve the energy resolution. Finally, the state of art development of 3-D position sensing and Compton imaging technique are also discussed. Spectroscopic performance of CdZnTe semiconductor detector will be greatly improved even to approach the statistical limit on energy resolution with the combination of some of these techniques.

show abstract

“…[2][3][4][5] For this application superior crystallinity and uniform high resistivity bulk material are required. [2][3][4][5] For this application superior crystallinity and uniform high resistivity bulk material are required.…”

Section: Introductionmentioning

confidence: 99%

Study of oxidized cadmium zinc telluride surfaces

Chen¹,

Shi²,

Chen³

et al. 1997

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

View full text Add to dashboard Cite

Cadmium zinc telluride has been developed as a room temperature radiation detector in recent years. The issue of decreasing surface leakage current, which affects the energy resolution of radiation response, was investigated extensively by various surface oxidation treatments. In this study, an aqueous solution of hydrogen peroxide (H2O2) was used in the oxidation of CdZnTe wafers in order to decrease surface leakage current. The surface chemical composition and its morphology modification due to this oxidation process were investigated. X-ray photoelectron spectroscopy analysis revealed that the main chemical species left after H2O2 oxidation are TeO2 along with a small amount of a Cd-related oxide. We found no obvious evidence of the presence of Zn-related oxides. The oxide thickness reaches a saturation after 5 min of H2O2 oxidation. The atomic force microscopy images revealed that, at this stage of saturation, the surface roughness and the mean diameter of the main features were about 1.3 μm and 97 nm, respectively. The decrease of 37% in the surface leakage current was related to the oxide layers formed by H2O2 oxidation.

show abstract

Signal generation in CdZnTe strip detectors

Cited by 29 publications

References 5 publications

CZT detectors used in different irradiation geometries: Simulations and experimental results

CZT detectors used in different irradiation geometries: Simulations and experimental results

Progress in the Development of CdZnTe Unipolar Detectors for Different Anode Geometries and Data Corrections

Study of oxidized cadmium zinc telluride surfaces

Contact Info

Product

Resources

About