Silicon Photonics: Fundamentals and Devices

2.1 Introduction

There are many textbooks, introductory and advanced, that deal with fundamental properties of solid-state materials including semiconductors. Research monograms are also available that emphasize one or two focused and important aspects of material silicon or a particular device using silicon. Since silicon and different structures using Si are invariably used in microelectronics, specialized textbooks discuss growth, materials and device characterization, the electronic properties of materials, device behavior, and so on.

The aim of the present book is to discuss the use of silicon and related materials in photonic devices. Therefore the optoelectronic properties of Si will be the subject of interest. In the present chapter, we plan to mention briefly the basic properties that may be useful in understanding the operation of Si-based photonic devices. It is not possible to cover an in-depth survey of all the important properties. Therefore, only the introductory ideas will be given, and the reader will be referred to proper sources for finer details.

The chapter begins with a brief introduction to the band diagram; specifically, the energy–wave vector (E–k) relationship will be described. The most important bands participating in electronic and optoelectronic processes and some of the useful parameters needed in further studies will be introduced.

Most of the modern optoelectronic and photonic devices rely on heterojunctions, that is, junctions between two dissimilar ...