# IEEE Transactions on Nuclear Science

## Volume 56 Issue 4  Part 1 • Aug. 2009

This issue contains several parts.Go to:  Part 2  | Part 3

## Filter Results

Displaying Results 1 - 25 of 36
• ### [Front cover]

Publication Year: 2009, Page(s): C1
| PDF (66 KB)
• ### IEEE Transactions on Nuclear Science publication information

Publication Year: 2009, Page(s): C2
| PDF (39 KB)

Publication Year: 2009, Page(s):1697 - 1699
| PDF (88 KB)
• ### Fast Neutron Damage of a Pixelated CdZnTe Gamma Ray Spectrometer

Publication Year: 2009, Page(s):1700 - 1705
| | PDF (627 KB) | HTML

This study describes the damage to a pixelated 1 cm times 1 cm times 1 cm CdZnTe detector caused by fast neutrons in the energy range 1-7 MeV. Measurements of electron mutau product were performed before and after irradiation and also following thermal annealing. Spectroscopic information was acquired with a 133Ba gamma source. Before neutron irradiation, sharp peaks were observed for t... View full abstract»

• ### Evaluation of the Concentration of Deep Levels in Semi-Insulating CdTe by Photoconductivity and TEES

Publication Year: 2009, Page(s):1706 - 1711
Cited by:  Papers (10)
| | PDF (236 KB) | HTML

The concentrations of near-midgap levels in high-resistivity CdTe were estimated based on a combined evaluation of room temperature lux-ampere characteristics and thermoelectric effect spectroscopy measurements (77-400 K). A simulation of experimental data was performed by a numerical solution of drift-diffusion and Poisson equations using a model with two deep levels. A comparison of crystals dop... View full abstract»

• ### Evaluation of Surface Recombination Velocity on CdTe Radiation Detectors by Time-of-Flight Measurements

Publication Year: 2009, Page(s):1712 - 1716
Cited by:  Papers (8)
| | PDF (232 KB) | HTML

The surface recombination velocity on high-resistivity CdTe with several different crystallographic orientations-(111), 5deg off from (111), 8deg off from (311), and (511)-has been investigated by using a ldquomutau-modelrdquo spectral fitting method in combination with time-of-flight drift mobility measurement. In the samples orientated parallel to (111) and 5deg off from (111), the Cd face exhib... View full abstract»

• ### THM Growth and Characterization of 100 mm Diameter CdTe Single Crystals

Publication Year: 2009, Page(s):1717 - 1723
Cited by:  Papers (25)
| | PDF (2037 KB) | HTML

The THM growth technology for 100 mm diameter CdTe single crystals has been intensively developed. In consequence of the optimization of growth conditions, we have succeeded in controlling growth interface shape and growing 100 mm diameter CdTe single crystals with 300 mm in length. Concerning the behavior of Te inclusions in the grown crystal, their size and density were investigated by IR transm... View full abstract»

• ### Compensation and Photosensitivity in CdTe Doped With Indium

Publication Year: 2009, Page(s):1724 - 1730
Cited by:  Papers (5)
| | PDF (452 KB) | HTML

To better our knowledge of the characteristics of semi-insulated cadmium telluride (CdTe) doped with indium (In), we explored the role of deep levels in compensation and trapping. We assessed the defects and their distribution across a wafer in several ways; by measuring dark resistivity and photosensitivity maps, photoluminescence, Photo-Induced Current Transient Spectroscopy (PICTS), and Thermoe... View full abstract»

• ### Electrical Properties of Iodine-Doped CdTe Epitaxial Films on Si Substrates Grown by MOVPE

Publication Year: 2009, Page(s):1731 - 1735
Cited by:  Papers (2)
| | PDF (430 KB) | HTML

We studied the effect of iodine doping of CdTe films on Si substrates grown by MOVPE at different growth conditions. A high resistivity film was obtained by adjusting the growth temperature, Te/Cd precursor flow ratio and the dopant flow-rate. Our results show the film resistivity does not change linearly with the dopant flow-rate. The resistivity remains low and similar to that of undoped value f... View full abstract»

• ### Study on Instability Phenomena in CdTe Diode-Like Detectors

Publication Year: 2009, Page(s):1736 - 1742
Cited by:  Papers (31)
| | PDF (597 KB) | HTML

Diode-like In/CdTe/Pt detectors are widely used thanks to their excellent spectroscopic performance. However, when operated at room temperature they are not stable, and their performance degrades with time. The aim of this paper is to investigate in detail the physical mechanisms underlying this effect, by studying the evolution of the space charge inside the detector. Our approach makes use of th... View full abstract»

• ### Boron Oxide Encapsulated Vertical Bridgman Grown CdZnTe Crystals as X-Ray Detector Material

Publication Year: 2009, Page(s):1743 - 1746
Cited by:  Papers (24)
| | PDF (863 KB) | HTML

Two-inch-diameter CdZnTe crystals doped with indium were grown by the boron oxide encapsulated vertical Bridgman technique. The crystals showed large single crystalline yield and low etch pit density. The background impurity content was dominated by boron in concentration lower than 1 ppm. High resistivity was obtained and a procedure for contact preparation was developed. The mobility-lifetime pr... View full abstract»

• ### Dewetting During the Crystal Growth of (Cd,Zn)Te:In Under Microgravity

Publication Year: 2009, Page(s):1747 - 1751
Cited by:  Papers (5)
| | PDF (1423 KB) | HTML

The phenomenon of ldquodewettingrdquo associated with the Vertical Bridgman (VB) crystal growth technique leads to the growth of a crystal without contact with the crucible. One dramatic consequence of this modified VB process is the reduction of structural defects within the crystal. It has been observed in several microgravity experiments for different semiconductor crystals. This work is concen... View full abstract»

• ### Electromigration of Mobile Defects in CdTe

Publication Year: 2009, Page(s):1752 - 1757
Cited by:  Papers (3)  |  Patents (2)
| | PDF (225 KB) | HTML

Electromigration of mobile charged defects in external electric field is investigated at various temperatures and biases in conductive undoped and semiinsulating In-doped CdTe, respectively. A set of electric contacts as potential probes arranged linearly along the sample was used for the detection of the drift of the local resistance modulation. The observed modulation drifting along the sample a... View full abstract»

• ### Preparation of Inclusion and Precipitate Free Semi-Insulating CdTe

Publication Year: 2009, Page(s):1758 - 1762
Cited by:  Papers (1)
| | PDF (279 KB) | HTML

Annealing conditions used for the preparation of semi-insulating CdTe after elimination of inclusions and precipitates are discussed. Second phase defects are eliminated by post-growth stoichiometric annealing and the semi-insulating CdTe is prepared by re-annealing under Te or Cd overpressure. In case of In-doped samples with high In concentration, semi-insulating CdTe with resistivity approximat... View full abstract»

• ### Multi-Species Diffusion in CdTe

Publication Year: 2009, Page(s):1763 - 1767
Cited by:  Papers (2)
| | PDF (181 KB) | HTML

We studied theoretically chemical self-diffusion and the diffusion of extrinsic atoms in CdTe. We compiled a general model describing the multi-species diffusion of arbitrary amounts of elements in a form optimized for numerical calculations and applied it to a model system of CdTe doped with slow- or fast-diffusing elements. The diffusion of slowly diffusing atoms was analyzed and compared with e... View full abstract»

• ### Investigation of Growth Conditions of CdTe Thick Films on Properties and Demands for X-Ray Detector Applications

Publication Year: 2009, Page(s):1768 - 1774
Cited by:  Papers (5)
| | PDF (5471 KB) | HTML

CdTe thick films were prepared by vacuum deposition on amorphous substrates using MBE technique. The growth was performed at different temperatures to investigate the development of the growth rate, surface morphology, structure and optical properties. Properties of films deposited with a single CdTe source are compared with films grown with an additional Cd source. The growth experiments are disc... View full abstract»

• ### Extended Defects in CdZnTe Radiation Detectors

Publication Year: 2009, Page(s):1775 - 1783
Cited by:  Papers (32)
| | PDF (5156 KB) | HTML

Large-volume CdZnTe (CZT) single crystals with electron lifetime exceeding 10 mus have recently become commercially available. This opened the opportunity for making room temperature CZT gamma-ray detectors with extended thicknesses and larger effective areas. However, the extended defects that are present even in the highest-quality material remain a major drawback which affects the availability ... View full abstract»

• ### Dopant Content and Thermal Treatment of ${rm Cd} _{1-{rm x}} {rm Zn} _{rm x} {rm Te} langle {rm In}rangle$: Effects on Point-Defect Structures

Publication Year: 2009, Page(s):1784 - 1790
Cited by:  Papers (2)
| | PDF (535 KB) | HTML

We measured, in the 873-1173 K temperature range, the temperature- and Cd vapor-pressure-dependences of the free electron density in single CdTe(In) crystals with different In contents. Increasing the cooling rate of the crystals and/or decreasing the well-defined Cd vapor pressure reduced the free-electron density. We interpreted and modelled these phenomena and the crystal's high-temperature ele... View full abstract»

• ### Development of 4-Sides Buttable CdTe-ASIC Hybrid Module for X-ray Flat Panel Detector

Publication Year: 2009, Page(s):1791 - 1794
Cited by:  Papers (4)  |  Patents (2)
| | PDF (1456 KB) | HTML

A 4-sides buttable CdTe-ASIC hybrid module suitable for use in an X-ray flat panel detector (FPD) has been developed by applying through silicon via (TSV) technology to the readout ASIC. The ASIC has 128 times 256 channels of charge integration type readout circuitry and an area of 12.9 mm times 25.7 mm. The CdTe sensor of 1 mm thickness, having the same area and pixel of 100 mum pitch, was fabric... View full abstract»

• ### Optimization of Medipix-2 Threshold Masks for Spectroscopic X-Ray Imaging

Publication Year: 2009, Page(s):1795 - 1799
Cited by:  Papers (11)
| | PDF (1075 KB) | HTML

Spectroscopic X-ray imaging enhances image contrast and provides advanced object information due to energy resolution. The Medipix-2 chip is a photon counting semiconductor detector and features two energy thresholds for energy selective imaging. The aim of this study is to present the development of optimized threshold adjustment masks with small energy windows of about 3 keV width using a monoch... View full abstract»

• ### Status of Direct Conversion Detectors for Medical Imaging With X-Rays

Publication Year: 2009, Page(s):1800 - 1809
Cited by:  Papers (35)
| | PDF (671 KB) | HTML

Imaging detectors for medical X-ray and computed tomography (CT) applications have undergone many improvements and technology changes over time. But most (dynamic) detectors sold in this field still rely on indirect conversion, using scintillators and photodiodes to convert the X-ray quanta ultimately into electrical signals. Direct conversion detectors promise very high spatial resolution and hig... View full abstract»

• ### Polycrystalline Mercuric Iodide Films on CMOS Readout Arrays

Publication Year: 2009, Page(s):1810 - 1816
Cited by:  Papers (8)
| | PDF (5899 KB) | HTML

We have created high-resolution x-ray imaging devices using polycrystalline mercuric iodide (HgI2) films grown directly onto CMOS readout chips using a thermal vapor transport process. Images from prototype 400 times 400 pixel HgI2-coated CMOS readout chips are presented, where the pixel grid is 30 mum times 30 mum. The devices exhibited sensitivity of 6.2 muC/Rcm2... View full abstract»

• ### Temperature Dependence in the Long-Term Stability of the TlBr Detector

Publication Year: 2009, Page(s):1817 - 1822
Cited by:  Papers (11)
| | PDF (302 KB) | HTML

In this paper, TlBr detectors with three-electrodes were prepared and their long term stability evaluated as a function of the temperature. Systematic measurements of counting rate were carried out to observe the random pulse formation, due to the polarization effect. Three-electrode detectors presented stability of about 112 h at near room temperature and more than 325 h at 0degC. Although the th... View full abstract»

• ### Study of Surface Treatment Effects on the Metal-CdZnTe Interface

Publication Year: 2009, Page(s):1823 - 1826
Cited by:  Papers (35)
| | PDF (349 KB) | HTML

The quality of a CdZnTe-based X-ray detector is highly related to the interface between semiconductor and metal contact. One of the factors that increase leakage currents in CdZnTe based X-ray detectors is the presence of a conductive surface layer. In this paper the result of the passivation of the CdZnTe surface by means of an aqueous solution of NH4F/H2O2 is stu... View full abstract»

• ### Higher Voltage Ni/CdTe Schottky Diodes With Low Leakage Current

Publication Year: 2009, Page(s):1827 - 1834
Cited by:  Papers (13)
| | PDF (275 KB) | HTML

A significant improvement in electrical characteristics of Schottky diodes designed for X- and gamma-ray detectors has been achieved using semi-insulating CdTe single crystals and unified technology, where both Schottky and near-ohmic contacts were formed by the deposition of the same metal (Ni) on the opposite surfaces of the crystal pre-treated by chemical etching and Ar ion bombardment with dif... View full abstract»

## Aims & Scope

IEEE Transactions on Nuclear Science focuses on all aspects of the theory and applications of nuclear science and engineering, including instrumentation for the detection and measurement of ionizing radiation; particle accelerators and their controls; nuclear medicine and its application; effects of radiation on materials, components, and systems; reactor instrumentation and controls; and measurement of radiation in space.

Full Aims & Scope

## Meet Our Editors

Editor-in-Chief
Paul Dressendorfer
11509 Paseo del Oso NE
Albuquerque, NM  87111  USA