The Characterization of Germanium and Silicon for Nuclear Radiation Detectors.

1982 ◽  
Vol 16 ◽  
Author(s):  
L. S. Darken
Keyword(s):  
High Purity ◽  
Deep Level ◽  
Radiation Detectors ◽  
Nuclear Radiation ◽  
Extended Defects ◽  
Pure Material ◽  
Photothermal Ionization Spectroscopy ◽  
Transient Spectroscopy ◽  
Nuclear Radiation Detectors

ABSTRACTSemiconductor nuclear radiation detectors require deep depletion depths (0.03–3.0 cm) and effective charge collection distances which are several times longer than these depletion depths. These requirements place stringent limitations on the net electrically active impurity concentration, and on the concentration of deep centers which can trap carriers generated by the incident nuclear radiation. This need for extremely pure material distinguishes the interests and efforts of the semiconductor detector community from the rest of the semiconductor community. This paper reviews the characterization of shallow-level, deep-level, neutral, and extended defects in germanium and silicon for nuclear radiation detectors. Photothermal ionization spectroscopy has been used extensively to identify the residual hydrogenic impurities in high-purity (∣NA–ND∣ ≈ 1010–1011 cm−3 ) germanium and silicon. Deep level transient spectroscopy has been effectively used to detect and identify deeper levels in high-purity germanium. Residual neutral defects are not necessarily passive: they may complex to form deep or shallow levels, they may precipitate, or they may act as nucleation sites for precipitation. The properties of extended defects (dislocations, lineage, inclusions, precipitates) and their effects on device performance are fundamentally less well understood, as the origin of the electrical activity of these defects is uncertain. It has been found in numerous instances that chemical interactions among defects are important even in these high-purity semiconductors.

Characterization of CdTe/n$^{+}$-Si Heterojunction Diodes for Nuclear Radiation Detectors

2007 ◽  
Vol 54 (4) ◽  
pp. 817-820 ◽  
Author(s):  
M. Niraula ◽  
K. Yasuda ◽  
K. Noda ◽  
K. Nakamura ◽  
I. Shingu ◽  
...  
Keyword(s):  
Radiation Detectors ◽  
Nuclear Radiation ◽  
Heterojunction Diodes ◽  
Nuclear Radiation Detectors

scholarly journals High-Purity Germanium Crystal Growing

1982 ◽  
Vol 16 ◽  
Author(s):  
W. L. Hansen ◽  
E.E. Haller
Keyword(s):  
High Purity ◽  
Charge Trapping ◽  
Solid Material ◽  
Radiation Detectors ◽  
Nuclear Radiation ◽  
Active Centers ◽  
Defect Complexes ◽  
Regular Production ◽  
And Control ◽  
Nuclear Radiation Detectors

ABSTRACTThe germanium crystals used for the fabrication of nuclear radiation detectors are required to have a purity and crystalline perfection which is unsurpassed by any other solid material. These crystals should not have a net electrically active impurity concentration greater than 10l0 cm−3 and be essentially free of charge trapping defects.Such perfect crystals of germanium can be grown only because of the highly favorable chemical and physical properties of this element. However, ten years of laboratory scale and commercial experience has still not made the production of such crystals routine. The origin and control of many impurities and electrically active defect complexes is now fairly well understood but regular production is often interrupted for long periods due to the difficulty of achieving the required high purity or to charge trapping in detectors made from crystals seemingly grown under the required conditions.The compromises involved in the selection of zone refining and crystal grower parts and ambients is discussed and the difficulty in controlling the purity of key elements in the process is emphasized. The consequences of growing in a hydrogen ambient are discussed in detail and it is shown how complexes of neutral defects produce electrically active centers.

The Effects of Illumination on Point Defects Detected in High Purity Semi-Insulating 4H-SiC

2018 ◽  
Vol 924 ◽  
pp. 253-256 ◽  
Author(s):  
Giovanni Alfieri ◽  
Lukas Kranz ◽  
Lars Knoll ◽  
Vinoth Kumar Sundaramoorthy
Keyword(s):  
Point Defects ◽  
High Purity ◽  
Deep Level Transient Spectroscopy ◽  
Optical Pulse ◽  
Deep Level ◽  
Electrical Characterization ◽  
Ionization Energies ◽  
Transient Spectroscopy

The electrical characterization of high-purity semi-insulating 4H-SiC is carried out by means of current deep level transient spectroscopy (I-DLTS). Measurements are performed by employing either an electrical or optical pulse (below/above bandgap). The study performed on as-grown material, either annealed or oxidized, reveals the presence of six levels with ionization energies in the 0.4-1.3 eV range.

Processing and Characterization of HgBrxI2−x Radiation Detectors

1993 ◽  
Vol 302 ◽  
Author(s):  
C. Zhou ◽  
M. R. Squillante ◽  
L. P. Moy ◽  
P. Bennett
Keyword(s):  
Energy Gap ◽  
Visible Spectrum ◽  
Radiation Detectors ◽  
Nuclear Radiation ◽  
Electrical And Optical Properties ◽  
Radiation Sources ◽  
Photoconductive Detectors ◽  
Ternary Semiconductor ◽  
Nuclear Radiation Detectors

ABSTRACTThis paper reports our recent work on the crystal processing, structural and optical characterization of HgBrxI2−x nuclear radiation detectors. To understand the electrical and optical properties of the detectors, we measured the energy gap of HgBrxI2−x as a function of the Br/I ratio. The energy band of this ternary semiconductor compound can be modulated from 2. 1eV (HgI2) to 3.4eV (HgBr2) by adjusting its chemical composition. This energy scope covers a wavelength spectrum between 365nm and 596nm, much of the visible spectrum. Nuclear and photoconductive detectors were fabricated from HgBrxI2−x single crystals and the responses of these devices were investigated with different radiation sources (241Am, 137Cs).

Low-Pressure Fast Growth and Characterization of 4H-SiC Epilayers

2010 ◽  
Vol 645-648 ◽  
pp. 77-82 ◽  
Author(s):  
Hidekazu Tsuchida ◽  
Masahiko Ito ◽  
Isaho Kamata ◽  
Masahiro Nagano ◽  
Tetsuya Miyazawa ◽  
...  
Keyword(s):  
Room Temperature ◽  
Deep Level ◽  
Fast Growth ◽  
Extended Defects ◽  
System Pressure ◽  
Transient Spectroscopy ◽  
Annealing Method ◽  
Fast Growth Rate

Fast and thick 4H-SiC epitaxial growth is demonstrated in a vertical-type reactor under a low system pressure within the range 13-40 mbar. A very fast growth rate of up to 250 m/h is obtained. The material quality of the epilayers grown in the reactor is evaluated by low-temperature photoluminescence, deep level transient spectroscopy, microwave photoconductive decay, synchrotron topography and room temperature PL imaging. The carrier lifetime of thick epilayers with or without the application of the C+-implantation/annealing method and extended defects in the epilayers grown on 8º and 4º off substrates are discussed.

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