Luminescent Spectroscopy of the Yb3+ Ions in the PbWO4 Crystal

Luminescent properties of the PbWO4 crystals undoped and doped with the Yb3+ ions were studied. Emission spectra of the crystals consist of broadband matrix emission in 350-750 nm spectral range and narrow spectral lines caused by inner electron transitions in the impurity Yb3+ ions in 920-1040 nm spectral range. Analysis of the linear spectra has shown that Yb3+ ions form two types of emission centres. Structures of these centers are discussed taking into account possibility of the impurity ions incorporation in different positions (Pb and W sites) in the crystal lattice. Effects of the Yb3+ impurities on matrix emission were studied. Transfer of excitation energy from matrix to the Yb3+ decreases intensity of the red band of matrix emission. The Yb3+ impurities also increase intensity of the blue band by formation of additional Yb3+-induced channel of excitation of this band. The described effects of Yb3+ doping on properties of matrix emission are caused by the Yb3+ ions arranged in Pb positions.