Broadband light output enhancement for scintillator using whispering‐gallery modes in nanospheres (Phys. Status Solidi A 7∕2014)

Abstract

Scintillators are a critical functional material in radiation detection systems, which are extensively used in nuclear medical imaging and high-energy physics experiments. The light output is very important for the sensitivity and signal-to-noise ratio. In spite of the high internal quantum efficiency for most of scintillators, the light output is still limited by the total internal refl ection due to the high refractive index. Zhichao Zhu et al. (pp. 1583–1588) experimentally demonstrate the broadband light extraction enhancement of Bi3Ge4O12 (BGO) scintillator by a monolayer array of polystyrene nanospheres. The authors reveal that whispering gallery modes (WGMs) for the individual sphere and the periodic arrangement are beneficial to the enhancement of light extraction, and WGMs play an important role in providing extra enhancement compared with a common two-dimensional photonic crystal. For example, an enhanced light extraction can lead to a lower radiation dose required in medical imaging, thus reducing the risk of cancer of the patients. The present work gives a good example for the application of photonic structures to the investigation of scintillators.