Self-trapped states and related luminescence in PbCl2 crystals -: art. no. 064304

We have comprehensively investigated localized states of photoinduced electron-hole pairs with the electron-spin-resonance technique and photoluminescence (PL) in a wide temperature range of 5-200 K. At low temperatures below 70 K, holes localize on Pb2+ ions and form self-trapping hole centers of Pb3+. The holes transfer to other trapping centers above 70 K. On the other hand, electrons localize on two Pb2+ ions at higher than 50 K and form self-trapping electron centers of Pb-2(3+). From the thermal stability of the localized states and PL, we clarify that the blue-green PL band at 2.50 eV is closely related to the self-trapped holes.