Absorption, reflection, excitation and polarization spectra of CdWO4 crysta
ls have been studied in the region 3.5-30 eV in order to distinguish betwee
n the excitonic and electron-hole processes in the vicinity of the band-gap
. An energy gap of 5 eV has been determined from the Urbach tail study at 1
00-300 K. Excitonic processes have been shown to dominate at lower energies
. A new fast emission band peaking at 3.6 eV has been found under pulsed el
ectron (300 keV, 3 ns) excitation and presumably ascribed to the metastable
oxyanionic exciton. (C) 2001 Elsevier Science Ltd. All rights reserved.