With a device-centric approach, this book begins by introducing the present challenges in Power Electronics, emphasizing the relevance of this discipline in today's scenario, and pointing out the key parameters to pay attention to from the application-design perspective. The next nine chapters dig into details, covering junction diodes, thyristors, silicon MOSFETs, silicon IGBTs, IGCTs, SiC diodes, SiC MOSFETs, GaN metal-insulator-semiconductor field-effect transistors (MIS-FETs), and GaN vertical transistors. A set of three chapters follow, covering key aspects from the designer's standpoint, namely module design and reliability, switching cell design, and IGBT gate-driving methods for robustness and reliability. A chapter outlining the prospects and outlooks in power electronics technology and its market concludes the book. This book addresses power device technology at the design level, by bridging the gap between semiconductor- and materials science, and power electronic applications. It provides key information for researchers working with power electronic devices and for power electronic application designers, and it is also a useful resource for academics and industrial researches working on power electronics at the system level, such as industrial machine designers and robot designers.