Semiconductor Physics and devices is a comprehensive textbook written for the undergraduate students of Electronics Engineering, electrical Engineering, applied Science, and materials Science. The book first provides a summary of the basic properties of semiconductor materials, covering energy band, carrier concentration, and transport properties, emphasizing Silicon and gallium arsenide. It then examines P-N diodes, bipolar transistors, MOSFET, and other field-effect transistors such as MOSFET, modefts, negative-resistance and power devices, and photonic devices and sensors, including Light-Emitting diodes, Photodetectors, and solar cells.