On the origin of the light yield enhancement in polymeric composite scintillators loaded with dense nanoparticles

TL;DR

This paper investigates how loading polymeric scintillators with dense hafnium dioxide nanoparticles doubles their light yield without affecting response time, revealing the local effect of nanoparticles in enhancing scintillation.

Contribution

It provides the first interpretation of the light yield enhancement mechanism in nanoparticle-loaded polymeric scintillators, highlighting the role of dense NPs in emissive state generation.

Findings

Scintillation yield increased by 100% with NPs

Time response remained unchanged

Nanoparticles influence emissive state formation

Abstract

Fast emitting polymeric scintillators are requested in advanced applications where high-speed detectors with large signal-to-noise ratio are needed. However, their low density implies a weak stopping power of high energy radiations, thus a limited light output and sensitivity. To enhance their performances, polymeric scintillators can be loaded with dense nanoparticles (NPs). We investigate the properties of a series of polymeric scintillators by means of photoluminescence and scintillation spectroscopy, comparing standard scintillators with a composite system loaded with dense hafnium dioxide (HfO2) NPs. The nanocomposite shows a scintillation yield enhancement of +100% with unchanged time response. We provide for the first time an interpretation of this effect, pointing out the local effect of NPs in the generation of emissive states upon interaction with the ionizing radiation. The obtained results indicate that coupling of fast conjugated emitters with optically inert dense NPs could allow to surpass the actual limits of pure polymeric scintillators.