Laser-induced infrared absorption in lead tungstate observed by laser-SR combined spectroscopy

Transient infrared absorption measurements are performed to study the photo-induced states in PbWO4 crystals at 16 K. A broad band is observed above 4000 cm−1, with a peak around 9000 cm−1. This band has a lifetime of 50 ms at 16 K, and disappears when the sample temperature is increased above 25 K. To investigate the origin of the photo-induced states, thermoluminescence is also measured after prolonged irradiation with 7.7-eV light at 8 K. Three glow peaks are observed at 15, 30, and 53 K. It is pointed out that the photo-induced band has a correlation with the 15-K glow peak, and is attributed to the (WO4)3− complex perturbed by another defect at the nearest-neighbor site.