The discovery of bright visible light emission from porous silicon has opened the door to various nanometer sized silicon structures where the confinement of carriers gives rise to interesting physical properties. While the high efficiency of the light emission in the visible range is the common and the most prominent feature, their structures display similar properties with other highly divided materials (even non semiconductors), and then justify a multidisciplinary approach. This along with potential applications has attracted a large number of researchers followed by students to be trained. Until now international conferences have provided the exchange of information but have remained highly specialised so it was time to give thought to the organisation of topical and advanced lectures where the multidisciplinarity and the didactic approach are paramount. L'ecole des Houches was ideally devoted to that purpose. The meeting : " Luminescence of porous silicon and silicon nanostructures" was the first international school on this topic but some aspects in the organisation and the attendance have given an international workshop flavor to it. The school by itself has trained 82 "students", most of them were students starting their Ph. D thesis. 50% were French citizens and the other represented countries were Germany, England, USA, Czechoslovakia, The Netherlands, Italy, Japan, Poland, Spain, Canada, Brazil, India and Russia.

The trend towards miniaturisation of microelectronic devices and the search for exotic new optoelectronic devices based on multilayers confer a crucial role on semiconductor interfaces. Great advances have recently been achieved in the elaboration of new thin film materials and in the characterization of their interfacial properties, down to the atomic scale, thanks to the development of sophisticated new techniques. This book is a collection of lectures that were given at the International Winter School on Semiconductor Interfaces: Formation and Properties held at the Centre de Physique des Rouches from 24 February to 6 March, 1987. The aim of this Winter School was to present a comprehensive review of this field, in particular of the materials and methods, and to formulate recom mendations for future research. The following topics are treated: (i) Interface formation. The key aspects of molecular beam epitaxy are emphasized, as well as the fabrication of artificially layered structures, strained layer superlattices and the tailoring of abrupt doping profiles. (ii) Fine characterization down to the atomic scale using recently devel oped, powerful techniques such as scanning tunneling microscopy, high reso lution transmission electron microscopy, glancing incidence x-ray diffraction, x-ray standing waves, surface extended x-ray absorption fine structure and surface extended energy-loss fine structure. (iii) Specific physical properties of the interfaces and their prospective applications in devices. We wish to thank warmly all the lecturers and participants, as well as the organizing committee, who made this Winter School a success."