Novel Approach Toward High Performance Energetic Rays Detection

72853-Ultrafast (sub-nanosecond), ultrahigh spatial resolution (sub-micron), and highly efficient scintillator detectors are required for many time-resolved energetic photon imaging and detection applications. However, current scintillator screens only can achieve spatial resolutions in the range of tens microns, response times in the range from hundreds nanoseconds to tens microsecond, and poor light collection efficiency (<65%). Near-band-edge emission semiconductor scintillators are promising materials that could overcome the above insufficiencies, but the fabrication of high quality materials is still a challenging task. This project will develop a novel nano-fabrication technology for fabricating direct wide bandgap semiconductor scintillator nanocrystal arrays. Such arrays potentially could achieve sub-micron spatial resolution, light output of approximately 200,000 photons per MeV, sub-nanosecond response, and, theoretically, 100% light collection efficiency. Phase I validated the proposed nanofabrication technology through the development of large area scintillator nanocrystal arrays for potential energetic photon detectors. The arrays were overcoated with optical filling materials, and then subjected to full scintillation characterizations. Phase II will fully develop functional nano-arrayed scintillator screens, characteriziang them in terms of fast and bright luminescent properties. Novel detection systems, based these innovative arrayed scintillator screens, will be developed, charcterized, and commercialized. Commercial Applications and Other Benefits as described by awardee: High spatial resolution and fast response speed are key luminescence characteristics for energetic photon and neutron detection and imaging. The nanoarrayed detectors should have extensive applications in nuclear detections, dynamic nondestructive tests, fast medical imaging, macro-crystallography, and fundamental research areas where resolution and speed are important.