While the first chapter of this book dwelt on the confirmation of the fundamental ideas of the philosophers of the fifth century BC, this last chapter will be devoted to the twentieth century and to the transformation of our materialistic everyday life brought about by electronics.

The early developments employed electronic tubes which owed nothing to surface physics and crystal growth. Then came the transistor and the realm of silicon, of which huge, dislocation-free crystals can be grown from the melt. In this end of the twentieth century, electromagnetic waves play an increasingly important part. Their production and detection require more and more complex semiconducting materials, often grown by molecular beam epitaxy.

Introduction

The modernity of surface science lies for a large part in the fact that new experimental techniques now make surfaces accessible to investigation. But the present interest in surface physics is also much motivated by the technological importance of crystals grown with a well-controlled composition and a high degree of perfection, and this depends very much on the state of the crystal surface during growth.

The purpose of this chapter is to outline the technological importance of materials with a controlled purity and morphology.

We shall mainly discuss semiconductors. It is not very easy to find simple articles or books explaining semiconductor electronics to the ignorant, but the book by Parker (1994) accomplishes this function.