Gnatyuk, V.; Maslyanchuk, O.; Solovan, M.; Brus, V.; Aoki, T. CdTe X/γ-Ray Detectors with Different Contact Materials. Sensors2021, 21, 3518.
Gnatyuk, V.; Maslyanchuk, O.; Solovan, M.; Brus, V.; Aoki, T. CdTe X/γ-Ray Detectors with Different Contact Materials. Sensors 2021, 21, 3518.
Gnatyuk, V.; Maslyanchuk, O.; Solovan, M.; Brus, V.; Aoki, T. CdTe X/γ-Ray Detectors with Different Contact Materials. Sensors2021, 21, 3518.
Gnatyuk, V.; Maslyanchuk, O.; Solovan, M.; Brus, V.; Aoki, T. CdTe X/γ-Ray Detectors with Different Contact Materials. Sensors 2021, 21, 3518.
Abstract
Different contact materials along with optimization of the deposition techniques expand the possibilities to obtain high performance room temperature CdTe-based X/γ-ray detectors. The heterostructures with ohmic (MoOx) and Schottky (MoOx, TiOx, TiN, and In) contacts, created by DC reactive magnetron sputtering and vacuum thermal evaporation, as well as In/CdTe/Au diodes with a p-n junction, formed by laser-induced doping, were developed and investigated. Depending on the pre-treatment of the surface of semi-insulating p-CdTe crystals, deposition of a MoOx film formed an ohmic or Schottky contact. Based on the calculations and IV characteristics of the fabricated Mo-MoOx/р-CdTe/MoOx-Mo, In/CdTe/MoOx-Mo, Ti-TiOx/р-CdTe/MoOx-Mo, and Ti-TiN/р-CdTe/MoOx-Mo Schottky-diode detectors, the current transport processes were described in the models of the carrier generation-recombination within the space-charge region (SCR) at low bias voltages, and space-charge limited current at higher voltages, respectively. The energies of generation–recombination centers, density of trapping centers, and carrier lifetimes were determined. A sharp increase in the reverse current in the Mo-MoOx/р-CdTe/MoOx-Mo, Ti-TiOx/р-CdTe/MoOx-Mo, and Ti-TiN/р-CdTe/MoOx-Mo heterostructures at high bias was discussed in frames of the Poole–Frenkel emission model. Nanosecond laser irradiation of the In electrode, pre-deposited on the p-CdTe crystals, resulted in an increase in the voltage range, corresponding to the carrier generation-recombination in the SCR, in the IV characteristics of the In/CdTe/Au diodes. Such In/CdTe/Au p-n junction diodes demonstrated high energy resolutions (7%@59.5 keV, 4%@122 keV, and 1.6%@662 keV).
Keywords
CdTe detectors; X-ray and gamma ray spectroscopy; Schottky contact; p-n junction; charge transport mechanism
Subject
Physical Sciences, Acoustics
Copyright:
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