Bridgman-Grown : A Comparison of Suitability for X and Gamma Detectors

• Published in: Sensors (Basel, Switzerland) Vol. 24; no. 2
• Main Authors: Masłowska, Aneta, Kochanowska, Dominika M, Sulich, Adrian, Domagala, Jaroslaw Z, Dopierała, Marcin, Kochański, Michał, Szot, Michał, Chromiński, Witold, Mycielski, Andrzej
• Format: Journal Article
• Language: English
• Published: MDPI AG 01-01-2024
• Subjects: Bridgman, P.W; Detectors; Diffraction; Gamma rays; Medical equipment and supplies industry; Medical test kit industry; Photoluminescence; X-rays; Netherlands; Poland
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s24020345

This study explores the suitability of (Cd,Mn)Te and (Cd,Mn)(Te,Se) as room-temperature X-ray and gamma-ray detector materials, grown using the Bridgman method. The investigation compares their crystal structure, mechanical and optical properties, and radiation detection capabilities. Both crystals can yield large-area single crystal samples measuring approximately 30 × 30 mm[sup.2]. In low-temperature photoluminescence analysis, both materials showed defect states, and annealing in cadmium vapors effectively eliminated donor–acceptor pair luminescence in (Cd,Mn)Te but not in (Cd,Mn)(Te,Se). Moreover, harder (Cd,Mn)(Te,Se) exhibited a higher etch pit density compared to softer (Cd,Mn)Te. X-ray diffraction examination revealed uniform lattice constant distribution in both compounds, with variations at a part per million level. (Cd,Mn)Te crystals demonstrated excellent single crystal properties with narrower omega scan widths, while (Cd,Mn)(Te,Se) exhibited a high contribution of block-like structures with significantly larger misorientation angles. Spectroscopic evaluations revealed better performance of a pixelated (Cd,Mn)Te detector, in comparison to (Cd,Mn)(Te,Se), achieving a mean full width at half maximum of 14% for the 122 keV gamma peak of Co-57. The reduced performance of the (Cd,Mn)(Te,Se) detector may be attributed to deep trap-related luminescence or block-like structures with larger misorientation angles. In conclusion, Bridgman-grown (Cd,Mn)Te emerges as a more promising material for X-ray and gamma-ray detectors when compared to (Cd,Mn)(Te,Se).