Evaluation of photoluminescence and scintillation properties of Yb2+-doped CsMX3 (M = Ca, Sr; X = Cl, Br) crystals

Abstract

The photoluminescence (PL) and scintillation properties of CsMX3:Yb2+ (M = Ca, Sr; X = Cl, Br) crystals grown using a self-seeding solidification method were demonstrated. During PL and scintillation, spin-allowed and spin-forbidden Yb2+ 4f14–4f135d transitions were observed for CsCaBr3:Yb2+ and CsSrBr3:Yb2+, whereas only spin-forbidden transitions were observed for CsCaCl3:Yb2+ and CsSrCl3:Yb2+. The scintillation decay time constants of the spin-allowed transitions for CsCaBr3:Yb2+ and CsSrBr3:Yb2+ were 210 and 64 ns, respectively, while those for the spin-forbidden transitions of CsMX3:Yb2+ (M = Ca, Sr; X = Cl, Br) were between 57 and 390 μs? Based on the pulse height spectra, light yields of CsMX3:Yb2+ (M = Ca, Sr; X = Cl, Br) were estimated to be between 2700 and 5500 photons/MeV. When the slow components were considered, the estimated range increased to 16,000–120,000 photons/MeV. CsCaCl3:Yb2+ and CsCaBr3:Yb2+ showed high total light yields of 48,000 and 120,000 photons/MeV, respectively, when compared to CsSrCl3:Yb2+ and CsSrBr3:Yb2+, for which the obtained yields were 16,000 and 23,000 photons/MeV, respectively. Owing to their high light yields, CsMX3:Yb2+ (M = Ca, Sr; X = Cl, Br) crystals, including the slow components, therefore have the potential to replace conventional scintillators in current-mode detectors.