If you are an EE sophomore/junior or senior and want to buy a book on semiconductor physics or devices that is both comprehensive in its depth and coverage of topics, I'd highly recommend this book.
Op-Amps and Linear Integrated Circuits
Electronics Devices And Circuits
Microelectronic Circuits
Integrated electronics : Analog and Digital Circuit and system
Electrical Engineering (GATE Solved Papers)
The Performance And Design Of Alternating Current Machine