  An increasing number of applications of scintillators at low temperatures,
particularly in cryogenic experiments searching for rare events, has motivated
the investigation of scintillation properties of materials over a wide
temperature range. This paper provides an overview of the latest results on the
study of luminescence, absorption and scintillation properties of materials
selected for rare event searches so far. These include CaWO4, ZnWO4, CdWO4,
MgWO4, CaMoO4, CdMoO4, Bi4Ge3O12, CaF2, MgF2, ZnSe and AL2O3-Ti. We discuss the
progress achieved in research and development of these scintillators, both in
material preparation and in the understanding of scintillation mechanisms, as
well as the underlying physics. To understand the origin of the performance
limitation of self-activated scintillators we employed a semi-empirical model
of conversion of high energy radiation into light and made appropriate
provision for effects of temperature and energy transfer. We conclude that the
low-temperature value of the light yield of some modern scintillators, namely
CaWO4, CdWO4 and Bi4Ge3O12, is close to the theoretical limit. Finally, we
discuss the advantages and limitations of different materials with emphasis on
their application as cryogenic phonon-scintillation detectors (CPSD) in rare
event search experiments.
