Luminescence properties of Pb2+ based aggregates in CsI host crystals

Luminescence centers were created in the CsI host crystals by annealing of Pb-doped crystals at 400°C in air. It was found that the excitation spectra of these luminescence centers are coincided well with the excitation absorption of a series of compounds in the Cs-Pb-I system, which indicates that they are attributed to the creation of CsPbI3, CsPbI6 and other aggregates in the annealing process. The emission spectra of Pb:CsI crystals were measured in the 10-30 K temperature range by 360 nm and 410 nm excitation respectively. The relative intensities of emission bands depend strongly on annealing time, which implies that the creation and transformation of bands depend strongly on annealing time, which implies that the creation and transformation of various Pb-based aggregates in Pb:CsI crystals tend to active around 400°C annealing temperature.