1. For a survey on the exciting development of this field see the Proceedings of the International Conferences on Modulated Semiconductors (MSS) published since 1985: Proc. MSS-2, Ed. H. Saki (North-Holland, Amsterdam, 1986); Surf. Sci. 174 (1986); Proc. MSS-3, Eds. A. Raymond and P. Voisin (Ed. Physique, Les Ulis, 1987) J. Physique 48, Colloque C5 (1987); Proc. MSS-4, Eds. L. L. Chang, R. Merlin, and D. C. Tsui (North-Holland, Amsterdam, 1990); Surf. Sci. 228 (1990); Proc. MSS-5, Eds. S. Hiyamizu and H. Nakashima (North-Holland, Amsterdam, 1992) Surf. Sci. 267 (1992); Proc. MSS-6, Eds. G. Abstreiter and E. Gornik (Pergamon, Elsevier, Exeter, GB, 1994); Solid State Electron. 37, 523 — 1344 (1994)
2. This development is best recognized from the Proceedings of the International Conferences on the Physics of Semiconductors (ICPS) published since 1990: Proc. ICPS-20, Eds. E. M. Anastassakis and J. D. Joannopoulos (World Scientific, Singapore, 1990); Proc. ICPS-21, Eds. P. Jiang and H.Z. Zheng (World Scientific, Singapore, 1992); Proc. ICPS-22, Ed. D.J. Lockwood (World Scientific, Singapore, 1994)
3. The concept of wavefunction or band-gap engineering was first proposed by H. Sakaki, Proc. Int. Symp. Foundations Quantum Mechanics, Adv. Microfabr. Microstruct. Phys., Eds. S. Kamefuchi, H. Ezawa, Y. Murayama, M. Namiki, S. Nomura, Y. Ohnuki, and T. Yajima (Phys. Soc. Jpn., Tokyo, 1984) p. 94; and subsequently exploited by F. Capasso, Science 235, 172 (1987)
4. A.Y. Cho and J.R. Arthur, Progr. Solid State Chem. 10, 157 (1975); K. Ploog, in Crystals, Growth, Properties, and Applications, Ed. H.C. Freyhardt (Springer-Verlag, Berlin, 1980) p. 73
5. G.B. Stringfellow, Organometallic Vapor Phase Epitaxy: Theory and Practice (Academic Press, Boston, 1989)