The luminescence of CaWO4: Bi single crystals

Influence of doping with Bi3+ ions and Bi3+–Na+ or Bi3+–Li+ ions pairs on luminescence, emission kinetics and light yield of CaWO4 crystals has been investigated. It has been shown that under excitation in the A-band at 272 and 287 nm, related to the Bi3+ ions absorption, the luminescence peaked at 468 nm decaying with time image μs is observed. For bismuth concentration 50–500 ppm and the equimolar concentrations of the Bi3+ ions accompanied by Na+ or Li+ ions compensators the significant suppression of the phosphorescence peaked at 520 nm, related to the defect WO3–VO complex, and an improvement of scintillation characteristics of the CaWO4 are noticed. Energy transfer from the defect WO3–VO and regular WO42− oxy-anions to Bi3+ ions have been observed at room temperatures and discussed.