Abstract:
Characterization of deep-level defects in semiconductor materials is at the heart of
modern semiconductor science and technology due to their influence in the electronic
properties of these materials. Photoluminescence spectroscopy is a powerful technique for
the characterization and detailed understanding of the nature of the shallow and deep-level
defects in semiconductors.
In this project we have carried out experiments using the photoluminescence (PL)
technique, providing valuable experience to the research students in the semiconductor
physics laboratory and yielding interesting data. It may be added that this marked an
exciting new development since it is for the first time in Pakistan that the
photoluminescence spectroscopy technique has been introduced. The work carried out
under the project consists of following main parts:
(a) A detailed PL study was undertaken to characterize the silver defect system in
silicon.
(b) A detailed photoluminescence investigation of the effects of Al doping on GaAs
grown by molecular beam epitaxy (MBE-GaAs) was carried out. Crystals with 0.1%, 1% and
3% Al doping have been studied. Our study on these materials presents results on the
optical characteristics of the lowest Al composition GaAs reported to date.
(c) Some preliminary investigations have been carried out on the effect of alphairradiation on the photoluminescence properties of both n- and p-type InP.
