We have so far received many comments and feedback on our book from all quarters including students, instructors and, of course, many friends. We are most grateful to them not only for their compliments but also for their valu able criticism. We also received many requests for an instructor manual and solutions to the problems at the end of each chapter. We realize that semicon ductor physics has continued to evolve since the publication of this book and there is a need to continue to update its content. To keep our readers informed of the latest developments we have created a Web Page for this book. Its ad dress (as of the writing of this preface) is: http://pauline.berkeley.edultextbook. At this point this Web Page displays the following information: 1) Content, outline and an excerpt of the book. 2) Reviews of the book in various magazines and journals. 3) Errata to both first and second printing (most have been corrected in the second edition as of this date). 4) Solutions to selected problems. 5) Additional supplementary problems.
