A 'Cook's Tour' of Two Decades of Research into the Optical Properties of Nanostructured Silicon Materials

摘要

Amongst a number of diverse approaches to engineering efficient light emission in silicon nanostructures, one system that has received considerable attention has been Si/SiO_2 quantum wells. Engineering such structures has not been easy, because to observe the desired quantum confinement effects, the quantum well thickness has to be less than 5 nm. Nevertheless, such ultra thin structures have now been produced by a variety of techniques. The SiO_2 layers are amorphous, but the silicon layers can range from amorphous through nanocrystalline to single-crystal form. The fundamental band gap of the quantum wells has been measured primarily by optical techniques and strong confinement effects have been observed. A detailed comparison is made between theoretical and experimental determinations of the band gap in Si/SiO_2 quantum wells. The review article is prefaced with a historical account of the Pits and Pores Symposium series and a personal academic history of the author.