CdSe/CdZnS core/shell nanocrystal scintillators: Light yield, decay time, and solvent effects

Abstract

Semiconductor nanocrystals (NCs) have emerged as promising candidates for next-generation scintillators owing to their tunable band gaps and high photoluminescence quantum yields (PLQYs). However, most NC-based scintillators rely on polymer or solvent matrices, in which inefficient energy transfer and self-absorption significantly limit their light yield. In this study, we developed solvent- and polymer-free CdSe/CdZnS NC films (50-200 mu m thick) and quantitatively evaluated their gamma-ray response and its light yield through single-photoelectron (SPE)-based measurements. The NC films preserved their intrinsic optical characteristics after fabrication and exhibited distinct photopeaks at 59.5 keV (Am-241) and 81.0 keV (Ba-133), achieving a light yield of approximately 3200 +/- 100 photons/MeV with a fast decay time of similar to 20 ns-comparable to reported NC/polymer nanocomposite scintillators. We further investigated solvent effects using NC-doped liquid scintillators, revealing the importance of solvent selection for observing measurable scintillation signals.