Jf. Bresse et al., CATHODOLUMINESCENCE MICROSCOPY AND SPECTROSCOPY OF SEMICONDUCTORS ANDWIDE BANDGAP INSULATING MATERIALS, Mikrochimica acta, 1996, pp. 135-166
Cathodoluminescence (CL) corresponds to the emission of photons observ
ed from semiconductors and wide bandgap insulating crystals exposed to
an electron bombardment. The radiative de-excitation of the created h
ole-electron pairs may occur according to an intrinsic mechanism (dire
ct band to band recombination) or may be an extrinsic mechanism involv
ing charge recombination through energy levels associated with impurit
ies or point defects. For low bandgap materials, local analysis of sem
iconductor physical properties such as surface (interface) recombinati
on velocity and minority carrier diffusion length are studied by means
of CL measurements at different incident electron energies. For wide
bandgap insulators the complementarity of CL and X-ray spectrometries
is illustrated for the case of the localisation of trace elements and
for the case of charging phenomena related to the presence of pre-exis
ting point defects and induced defects during the electron bombardment
. Examples of CL microscopy and spectroscopy applied to the microchara
cterisation of semiconductors (GaAs, InP and related materials) and of
synthetic and natural mineral materials (ZnS, SiO2, rare-earth bearin
g crystals), are presented.