Effects of pre-anneal treatment on the optical characteristics of lead tungstate single crystal

We present the pre-annealing growth condition dependence of the optical pro perties of lead tungstate PbWO4 (shortly, PWO) single crystal. The colors o f PWO crystals were influenced by the pre-annealing time before melting of initial powder. The oxygen vacancy of PWO single crystal constituents is su ggested to be mainly responsible for the yellowish coloration that is relat ed to the absorption hand around 430 nm. The ratio of lead and oxygen vacan cy might also affect the PWO coloration. PbWO4 single crystals grown by the different growth conditions have shown a slight different lattice paramete r confirmed by X-ray diffraction method (XRD). Photoluminescence (PL) inten sities of the yellowish PWO were weaker than the colorless one. It is assum ed that there are different main trap levels related to the yellowish PWO s ingle crystal compared to colorless ones through thermoluminescence (TL) me asurements. (C) 2001 Elsevier Science B.V. All rights reserved.