We hope the book serves the purpose for which it has been written, namely, to be of use for practicing teachers and students interested in learning the Fundamentals of the Semiconductor Devices. Feedback, both from teachers and students, in the form of suggestions, criticisms and appreciationare most welcome. They can be sent either to Prof. M.K.Achuthan at mkapkm@vsnl.com. or to Prof. K.N.Bhat at knbhat@gmail.com. or posted directly to the Web site.