Development of self-activated Tl2ZnCl4 and Tl3ZnCl5 scintillators

Abstract We report the photoluminescence and scintillation properties of two new self-activated scintillators, based on Tl2ZnCl4 and Tl3ZnCl5 crystals with large effective atomic numbers (Zeff = 73.2 and 74.6, respectively), for application in X- and gamma-ray detection. The emission bands of the Tl2ZnCl4 and Tl3ZnCl5 crystals were observed at 472 nm. The peak wavelengths were characteristic of self-activated thallium-based chloride crystals. The estimated light yields of the Tl2ZnCl4 and Tl3ZnCl5 crystals were approximately 10,000 and 2100 photons/MeV, respectively. The light yield measured for Tl2ZnCl4 matches that of commercially available scintillators, such as Gd2SiO5(Ce) (10,000 photons/MeV).