An Introduction to the Physics and Electrochemistry of Semiconductors

Book Preface

Life has made me realize that the best way tolearn is to teach. During my 30 years of teaching at IIT Bombay as a professor in chemistry to MTech energy students, especially topics such as photovoltaic solar cells and photoelectrochemical (PEC) solar cells, I realized the necessity of writing a specific book so as to expose the students to the physics and electrochemistry of semiconductors, an understanding of which is needed to develop wet-type photovoltaic solar cells.

Physics and Electrochemistry of the Semiconductor and Its Application was written with a view to helping researchers and students understand the basics of physics in developing a PEC solar cell, including the electrochemistry of metals and semiconductors, a knowledge required for understanding the basic principles of a PEC cell. While dealing with PEC cells, it is also necessary to understand some specific electronic and electrochemical methods needed to interpret the equivalent circuits of a PEC cell. Finally, it is also necessary to study the various applications of PEC cells, in addition to generating electrical power from solar rays, such as carrying out certain one-step syntheses that conventionally may comprise more than a few steps. Application of photochromism is another area needing development, in which the least effort has been made by presentday researchers. Dye-sensitized solar cells are also becoming very popular. This science has developed many highly efficient solar cells, which are also discussed.

My effort has been to highlight some specific questions that are normally in the mind of the purchaser, such as the following.

What is the theme and scope of this book? This book was written with the intention of including only relevant topics in the fundamentals of the physics of semiconductors and of electrochemistry needed for understanding the intricacy of the subject of PEC solar cells. Readers interested in carrying out either teaching or research in the electrochemistry of semiconductors will find this book extremely handy.

What prompted the undertaking of writing this book? I had been teaching MTech students and MSc students of physics and chemistry at IIT Bombay, giving them the basic concepts of semiconductors, p:n junctions, PEC solar cells, electrochemistry of semiconductors, and photochromism. Students in this course were coming from various disciplines. It was very difficult to prescribe for them a suitable textbook, not because there are no books on these topics, but because they are either too exhaustive or very elementary. Students wanted something that dealt with the topics needed in their own specific fields. Faced with such a demand, I started writing this book, and students in my class found it very useful. I was enthused by this to further compile my lecture notes into book form.

What special features are covered? Students carrying out research or engaged in teaching PEC cells or knowledge of our sun, its energy, and its distribution to the earth will find essential topics such as the physics of semiconductors, the electrochemistry of semiconductors, p:n junctions, Schottky junctions, the concept of Fermi energy, and photochromism and its industrial applications. It is very difficult to get all this information into one book, but this book covers all these topics; hence this book could be considered many books in one. This book does not need a teacher to explain the subjects. Some examples are humorous in style, which helps the student relate to the topic. Students will like such examples because they will help them to remember the intricacy of the subject.

What new approaches are taken in this book? Most of the books dealing with these topics assume some minimum knowledge from students. Because I was teaching this subject to multidisciplinary students, I had to begin by assuming that students did not have a common knowledge base. This book does not need much by the way of basic concepts, because it starts almost from the beginning. I have noticed that students of my class like this approach.

This book is suitable as a textbook for students interested in learning these special topics at various levels, undergraduate or postgraduate, such as MTech, BTech, or MSc (chemistry and/or physics), and also for teachers from colleges, universities, and IITs. It will also be suitable for R&D industries dealing with electrochemistry, the physics of semiconductors, the electrochemistry of semiconductors/metals, photovoltaic solar cells, and photchromism and its applications.