Study on the photoluminescence of Cr³⁺ and doping mechanism in F^– codoped PbWO₄ single crystal

Abstract

The influence of Cr3+ and F– codoping on the defect structures in PbWO4 crystal is investigated by X‐ray diffraction and Fourier transform infrared (FTIR) spectroscopy and consequently a doping mechanism is proposed that the Cr3+ ions predominantly occupy the W6+ sites due to the help of F–. Photoluminescence (PL) spectra of PWO:Cr,F demonstrates in addition to the intrinsic luminescence from the PbWO4 crystal, a new sharp emission band at 15500 cm–1 can be observed even at room temperature and it may originate from the spin‐forbidden 2E → 4A2 radiation of Cr3+ in a strong crystal field. It suggests that the F– codoping makes a large contribution to the 2E → 4A2 luminescence of Cr3+ in the scheelite‐structural PWO single crystal. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Enhanced and Long‐Lived Near‐Infrared Luminescence of Er3+ Ions in Lead Borate Glass‐Ceramics Containing PbWO4 Nanocrystals

“…Influence of F − , Cl − , I − , and S 2− doping on the structure and properties was stated in the PbWO 4 single crystals. A doping mechanism was proposed that the Cr 3+ ions predominantly occupy the W 6+ sites in PbWO 4 crystals due to the help of F − . These results were also confirmed by other research that attributed mechanism of the charge compensation to the Me 2+ ‐ Ln 3+ exchange: addition of potassium halide KX (where X denotes F, Cl, Br or I) to system containing BaMoO4:Pr 3+ crystalline phase strengthens red emission of Pr 3+ .…”