Luminescence spectra of PbFCl single crystal under the excitation of synchrotron radiation VUV-UV

The luminescence spectra of PbFCl single crystal under the excitation of synchrotron radiation vacuum ultraviolet ultra violet (VUV-UV) were investigated. The emission spectra of PbFCl single crystal show a broad violet band peaking at 400 nm having decreasing intensity with the rising temperature being from 20 to 293 K under the excitation of VUV-UV. A weak ultraviolet band peaking at 325 nm, which can be ascribed to the cation exciton emission of Pb2+, appears at 20 K under the excitation at wavelength shorter than 247 nm, but is completely quenched above 60K. The violet band emission due to energy transfer from cation exciton was observed, which became more effective above 60 K. The luminescence in the violet band may be due to STE luminescence or is probably associated with the Pb2+ ion close to the Schottky-like defect. (c) 2005 Elsevier B.V. All rights reserved.