Copper iodide semiconductor: a non-hygroscopic, bright red-emitting scintillator for X-ray and gamma-ray detection

In this work, the inverse temperature crystallization and scintillation properties of copper iodide (CuI) semiconductors are presented. Single crystal of a γ-CuI is very attractive for X- and gamma-ray detection applications due to its non-hygroscopic and excellent light yield with long-wavelength emission in the red. The grown crystal shows an almost colorless and transparent feature and exhibits a red emission band peaking at 730 nm with a fluorescence quantum efficiency (QE) of 43% under excitation at 416 nm. The photoluminescence (PL) decay time constant was estimated to be approximately 175 ns (20%) and 2507 ns (80%) using an exponential fitting. The X-ray excited scintillation band appeared near the wavelength of 720 nm. The scintillation light yield reached 80000 photons MeV^-1 compared with a CsI:Tl commercial scintillator.