This paper reports spectroscopic and scintillation studies of the well
established scintillator material YAlO3:Ce. Standard measurements of
luminescence emission and excitation spectra have been accompanied by
investigations of thermoluminescence and scintillation light yield ove
r a wide temperature range, and by decay measurements under pulsed gam
ma and VUV excitations at various temperatures. These measurements are
interpreted in the framework of a model that includes a recombination
centre (Ce3+) and a number of electron traps. We demonstrate that som
e unusual and largely unexplained features of the YAlO3:Ce scintillato
r, such as a substantial disparity between scintillation and radiative
decay times, the presence of slow components in scintillation decays,
and a strong temperature variation of scintillation light yield betwe
en 150 and 300 K, have their origin in the processes of charge carrier
capture and emission by electron traps. Although the nature of these
traps remains elusive, most of the trap parameters, such as frequency
factors, energy depths, and relative populations, have been estimated.
This makes it possible to predict the characteristics of trap-free ma
terial and thereby the potential improvements that could be achieved.