Development of Large Volume, High Performance Monolithic CZT Radiation Detector

Area of Science:

• Materials Science
• Nuclear Instrumentation
• Medical Physics

Background:

• Cadmium Zinc Telluride (CZT) is a semiconductor material crucial for radiation detection.
• The traveling heater method (THM) is employed for growing high-quality CZT crystals.
• Improving energy resolution in CZT detectors is essential for advanced imaging and spectroscopy.

Purpose of the Study:

• To report recent progress in CZT radiation sensor development using the THM.
• To demonstrate enhanced detector performance through depth of interaction correction.
• To showcase applications in gamma spectroscopy and medical imaging.

Main Methods:

• Fabrication of large volume monolithic pixelated CZT detectors (40×40×15 mm³).
• Implementation of depth of interaction (DOI) correction techniques.
• Characterization of detector performance, including energy resolution at various energies.

Main Results:

• Initial gamma spectroscopy response showed < 2.5% energy resolution at 662 keV.
• After DOI correction, pixelated CZT detectors (22×22×15 mm³) achieved < 1% energy resolution at 662 keV.
• Pixelated detectors (20×20×6 mm³) for medical imaging demonstrated < 3% energy resolution at 122 keV.

Conclusions:

• Proprietary THM crystal growth and robust device fabrication yield high-performance CZT detectors.
• DOI correction is a key technique for significantly improving CZT detector resolution.
• Developed CZT detectors show promise for advanced gamma spectroscopy and medical imaging applications, including PET and SPECT.