THE CARRIER CAPTURE AND RECOMBINATION PROCESSES IN LN(3-ACTIVATED SCINTILLATORS())

The ability of activator ions to capture charge carriers and assume a different charge state under ionizing radiation is essential for effic ient performance of rare-earth (RE)-doped scintillator materials utili zing the carrier recombination energy. In this paper the sequence of c arrier trapping is discussed and interpreted using a simple, single-co nfiguration-coordinate model for two different cases: In one case (LuP O4:Ce, YAlO3:Ce, LuAlO3:Ce) the charge state involved in the scintilla tion mechanism is Ce4+, while in the other (LuPO4:Yb, YbPO4) it is Yb2 +. The possibility of a nonradiative recombination via Ce and Yb ions is also considered and found highly unlikely in accordance with experi mental results.