Cadmium telluride and cadmium zinc telluride

CdTe X/γ-ray Detectors with Different Contact Materials

“…The partial pressures of both argon and oxygen in the vacuum chamber during the deposition process were 400 mPa. The magnetron power was~150 W. The deposition process lasted for 10 min at the CdTe substrate temperature of~100 • C. In terms of the practical application of the developed CdTe-based structures for detection of X/γ-ray radiation, it is important to analyze the reverse branches of the I-V characteristics when the Schottky contact is biased positively with respect to the MoO x -Mo ohmic contact because of diode-type detectors operate under reverse bias [4][5][6][7][8]. It should be noted that the reverse currents in the heterostructures under investigation are equal to several nanoamperes at bias voltages of~50-100 V at room temperature (Figure 3).…”

“…In view of the perspectives of employing the developed X/γ-ray detectors for spectroscopy, it is important that the I-V characteristic of the Ti-TiN/p-CdTe/MoO x -Mo Schottkydiode detector is linear in the voltage range of 15 V < |V| < 110 V (Figure 4d). Substitution V = −10 V into Equation (4) shows that the width of the SCR equals~0.48 mm, i.e., at |V| > 10 V the depleted region occupies the entire thickness of the semiconductor crystal (d = 0.5 mm). In this case, the CdTe crystal behaves like a sample with a resistivity (R = (4-5) × 10 10 Ω) higher than that of the bulk (neutral) part of the semiconductor (R = (6-7) × 10 9 Ω).…”

“…The favorable features of semiconductor nuclear radiation detectors are: higher energy and spatial resolution, sufficient detection efficiency, satisfactory rate and timing characteristics, enhanced imaging capabilities, and promising ability to be fabricated as compact sensor modules for portable ionizing radiation detecting instruments operating at room temperature [1,2]. Among many suitable semiconductors, used for X/γ-ray (in other words, high-energy, nuclear, or ionizing radiation) detectors, cadmium telluride (CdTe) is the most studied, employed, and attractive compound because of its favorable physical properties [2][3][4][5][6]. Indeed, an optimal set of electrical and electronic characteristics of high-resistivity CdTe makes this material basic and still promising for compact uncooled X/γ-ray detectors covering a wide energy range from a few keV to tens MeV, which are widely used in science, industry, security, ecology, medicine, space astronomy and many other application fields [3][4][5][6][7][8].…”

“…Among many suitable semiconductors, used for X/γ-ray (in other words, high-energy, nuclear, or ionizing radiation) detectors, cadmium telluride (CdTe) is the most studied, employed, and attractive compound because of its favorable physical properties [ 2 , 3 , 4 , 5 , 6 ]. Indeed, an optimal set of electrical and electronic characteristics of high-resistivity CdTe makes this material basic and still promising for compact uncooled X/γ-ray detectors covering a wide energy range from a few keV to tens MeV, which are widely used in science, industry, security, ecology, medicine, space astronomy and many other application fields [ 3 , 4 , 5 , 6 , 7 , 8 ].…”

“…Among many suitable semiconductors, used for X/γ-ray (in other words, high-energy, nuclear, or ionizing radiation) detectors, cadmium telluride (CdTe) is the most studied, employed, and attractive compound because of its favorable physical properties [ 2 , 3 , 4 , 5 , 6 ]. Indeed, an optimal set of electrical and electronic characteristics of high-resistivity CdTe makes this material basic and still promising for compact uncooled X/γ-ray detectors covering a wide energy range from a few keV to tens MeV, which are widely used in science, industry, security, ecology, medicine, space astronomy and many other application fields [ 3 , 4 , 5 , 6 , 7 , 8 ]. Among the excellent features of this semiconductor, there are key advantages that should be highlighted: large atomic numbers of the compound components ( Z Cd = 48 and Z Te = 52) provide high absorption efficiency for X/γ-photons, stopping power and, therefore, high radiation attenuation coefficient; wide bandgap energy ( E g ~ 1.5 eV) and therefore, fairly high electrical resistivity (ρ > 10 9 Ω·cm) along with suitable charge transport properties allow CdTe-based detectors to operate without liquid nitrogen or Peltier cooling [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ].…”