Enhanced Scintillation Light Extraction Using Nanoimprinted Photonic Crystals

Abstract

The extraction of scintillation light from a crystal with high efficiency and low time jitter is vital for realizing much-needed gains in the performance of numerous radiation detection and imaging instruments that are vital components in medical imaging, industrial, and homeland security applications for the detection, localization, and energy classification of X-rays, γ-rays, or neutrons. Nanostructures such as photonic crystals (PhCs) maximize extraction of usable scintillation light that is otherwise lost when a high refractive index (RI) scintillator is coupled to a photodetector with low RI window. The PhC gradually changes the RI between the scintillator and photodetector, thereby substantially improving the light extraction efficiency, as well as the energy resolution (ER) and timing resolution. Here, we report on improvements in the light extraction and ER of inorganic scintillators using PhCs nanoimprinted in high RI polymers. Details of the design, fabrication, and characterization of the PhCs, the high RI polymers, and their impact on scintillator performance are presented here.