| The optical absorption and the steady-state luminescence properties of bismuth-doped, molybdenum-doped, and undoped CdWO4 crystals have been investigated from 4.8-K to 320-K. Three different excitation wavelengths (313-nm, 325-nm, and 351-run) were used. The intrinsic "blue" emission (near 490-nm at room temperature) was observed in all three samples. Excited with 351-nm light at 300-K, the undoped sample exhibited no significant emission. The Bi-doped sample exhibited a bright yellow emission near 560-nm due to transitions within the Bi3+ ions. The 325-nm excitation wavelength, at 5-K, gives rise to the "orange" emission originating in the transitions within the molybdate groups.;Infrared absorption bands due to OH- molecular ions have been investigated. Six OH- spectra were observed in the undoped and intentionally doped CdWO4. The trapping entities are the monovalent impurities Li+, Na+, and Cu+ substituting for the Cd2+, the pentavalent impurities Nb5+ and Ta5+ substituting for W 6+, and Cd vacancies. |
