Fabrication and luminescence properties of (K,Rb)2 CuCl3 single crystal scintillators with one-dimensional structures

(K,Rb)2CuCl3 single crystal scintillators with one-dimensional structures were successfully fabricated by the slow cooling method, and their luminescence properties were evaluated. Broad photoluminescence (PL) peaks were observed at 350-500 nm, and the highest PL quantum yields were 96.4 % for (K0.5,Rb0.5)2CuCl3 among the samples. Under X-ray irradiation, scintillation peaks attributed to the recombination of self-trapped excitons were observed within the range of 350-500 nm. Both PL and scintillation decay time constants were obtained to be 10-15 mu s. The best afterglow levels at 20 ms after X-ray irradiation for 2 ms were 5 ppm for (K0.75, Rb0.25)2CuCl3. The highest scintillation light yield was 16,000 photons/MeV for (K0.75,Rb0.25)2CuCl3 under 137Cs gamma-rays (662 keV) irradiation. The results indicate that (K,Rb)2CuCl3 single crystals are promising as scintillators with high LY, low afterglow, and no hygroscopicity.