Effect of CdTe crystal thickness on the efficiency of Cr/CdTe/Au Schottky-diode detectors
| Autor: | Volodymyr A. Gnatyuk, V.M. Sklyarchuk, Toru Aoki |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Physics
Nuclear and High Energy Physics 010308 nuclear & particles physics business.industry 05 social sciences Schottky diode 01 natural sciences Cadmium telluride photovoltaics Crystal Full width at half maximum Impurity 0502 economics and business 0103 physical sciences Electrode Optoelectronics business Instrumentation Ohmic contact 050203 business & management Diode |
| Zdroj: | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 953:163224 |
| ISSN: | 0168-9002 |
| DOI: | 10.1016/j.nima.2019.163224 |
| Popis: | The effect of CdTe crystal thickness on the detection efficiency and energy resolution of Cr/CdTe/Au diode X/ γ -ray detectors has been studied. The Schottky (Cr electrode) and near Ohmic (Au electrode) contacts were created using Ar plasma treatment of the B- and A-faces of CdTe(111) single crystals at different regimes, respectively. Detector-grade CdTe wafers with an area of 5 × 5 mm2 and thicknesses d of 0.5 mm, 0.75 mm, 1.0 mm and 2.0 mm were used. High energy resolution (FWHM) in the 137Cs spectra (662 keV peak) was achieved: from 0.5 % for thin detectors to 3.0 % for thick ones. From the comparison of the detection efficiency dependences on the CdTe crystal thickness with the corresponding calculated dependences, the uncompensated impurity concentration in CdTe was obtained as N ≈ 4 × 1010 cm−3. N determines the space–charge region width W in Schottky diodes, therefore the effect of this value on the detection efficiency was analyzed. A key feature of the efficiency calculation was the correct evaluation of the electric field strength in the crystals and also using the integration limit d rather than W when W > d (in contrast to the earlier works). |
| Databáze: | OpenAIRE |
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