ABSTRACT
This chapter describes two of the main strategies currently followed
to obtain an efficient light emission from Si-based materials.
The first approach is represented by Si nanocrystals (nc). Their
structural and photoluminescence (PL) properties are presented
and discussed, and their application for the fabrication of room tem-
perature operating light-emitting devices is proposed. Si-nc can be
efficiently excited by impactwith hot electrons, producing an intense
electroluminescence (EL) signal. Perspectives and performances
of these devices can be significantly enhanced by replacing Si-nc
with amorphous Si nanoclusters, since the latter nanostructures
are formed at lower temperature than Si-nc; furthermore, the
efficiency of light extraction from these devices can be significantly
increased by exploiting the properties of photonic crystals. The
second approach involves the introduction of rare earth ions into
properly chosen Si-based matrices. In this chapter, we discuss the
case of Er3+ ions embedded in a SiOx matrix, which allow to obtain intense PL and EL signals in the IR region, and of Eu2+ ions embedded in a SiOC matrix, whose strong and tunable emission in
the visible range allows to extend toward the low-wavelength side
the emission range usually covered by Si-nc and also to obtain a
high-quality white emission. The relevance and the impact of the
above approaches for the development of Si nanophotonics are
finally discussed.
